USB334x
Enhanced Single Supply Hi-Speed USB ULPI
Transceiver
Product Features
• USB-IF Battery Charging 1.2 Specification Compliant
• Link Power Management (LPM) Specification
Compliant
• Integrated ESD protection circuits
- Up to ±25kV IEC Air Discharge without external devices
• Over-Voltage Protection circuit (OVP) protects the
VBUS pin from continuous DC voltages up to 30V
• Integrated USB Switch (USB3341, USB3346, and
USB3347)
- Allows single USB port of connection by providing switching function for:
–Battery charging
–Stereo and mono/mic audio
–USB Full-Speed/Low-Speed data
• RapidCharge Anywhere™ Provides:
- 3-times the charging current through a USB
port over traditional solutions
- USB-IF Battery Charging 1.2 compliance to
any portable device
- Charging current up to 1.5Amps via compatible USB host or dedicated charger
- Dedicated Charging Port (DCP), Charging
(CDP) & Standard (SDP) Downstream Port
support
• flexPWR® Technology
- Extremely low current design ideal for battery
powered applications
- “Sleep” mode tri-states all ULPI pins and
places the part in a low current state
- 1.8V to 3.3V IO Voltage (USB3343)
• Single Power Supply Operation
- Integrated 1.8V regulator
- Integrated 3.3V regulator
–100mV dropout voltage
• PHYBoost
- Programmable USB transceiver drive
strength for recovering signal integrity
• VariSense™
- Programmable USB receiver sensitivity
• “Wrapper-less” design for optimal timing performance and design ease
- Low Latency Hi-Speed Receiver (43 HiSpeed clocks Max) allows use of legacy
UTMI Links with a ULPI bridge
2009-2018 Microchip Technology Inc.
• External Reference Clock operation available
- ULPI Clock Input Mode (60 MHz sourced by
Link)
- 0 to 3.6V input drive tolerant
- Able to accept “noisy” clock sources as reference to internal, low-jitter PLL
- Crystal support available (USB3343)
• Smart detection circuits allow identification of
USB charger, headset, or data cable insertion
• Includes full support for the optional On-The-Go
(OTG) protocol detailed in the On-The-Go
Supplement Revision 2.0 specification
• Supports the OTG Host Negotiation Protocol
(HNP) and Session Request Protocol (SRP)
• UART mode for non-USB serial data transfers
• Internal 5V cable short-circuit protection of ID, DP
and DM lines to VBUS or ground
• Industrial Operating Temperature -40C to +85C
• 24 pin, QFN RoHS Compliant package
(4 x 4 x 0.90 mm height)
Applications
The USB334x is the solution of choice for any application where a Hi-Speed USB connection is desired and
when board space, power, and interface pins must be
minimized.
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Cell Phones
PDAs
MP3 Players
GPS Personal Navigation
Scanners
External Hard Drives
Digital Still and Video Cameras
Portable Media Players
Entertainment Devices
Printers
Set Top Boxes
Video Record/Playback Systems
IP and Video Phones
Gaming Consoles
DS00002646A-page 1
USB334x
TO OUR VALUED CUSTOMERS
It is our intention to provide our valued customers with the best documentation possible to ensure successful use of your Microchip
products. To this end, we will continue to improve our publications to better suit your needs. Our publications will be refined and
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If you have any questions or comments regarding this publication, please contact the Marketing Communications Department via
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http://www.microchip.com
You can determine the version of a data sheet by examining its literature number found on the bottom outside corner of any page.
The last character of the literature number is the version number, (e.g., DS30000000A is version A of document DS30000000).
Errata
An errata sheet, describing minor operational differences from the data sheet and recommended workarounds, may exist for current devices. As device/documentation issues become known to us, we will publish an errata sheet. The errata will specify the
revision of silicon and revision of document to which it applies.
To determine if an errata sheet exists for a particular device, please check with one of the following:
• Microchip’s Worldwide Web site; http://www.microchip.com
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When contacting a sales office, please specify which device, revision of silicon and data sheet (include -literature number) you are
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DS00002646A-page 2
2009-2018 Microchip Technology Inc.
USB334x
Table of Contents
1.0 General Description ........................................................................................................................................................................ 4
2.0 Pin Locations and Definitions .......................................................................................................................................................... 7
3.0 Limiting Values .............................................................................................................................................................................. 13
4.0 Electrical Characteristics ............................................................................................................................................................... 15
5.0 Architecture Overview ................................................................................................................................................................... 24
6.0 ULPI Operation ............................................................................................................................................................................. 42
7.0 ULPI Register Map ........................................................................................................................................................................ 63
8.0 Application Notes .......................................................................................................................................................................... 77
9.0 Package Outline ............................................................................................................................................................................ 82
Appendix A: Data sheet Revision History ........................................................................................................................................... 88
2009-2018 Microchip Technology Inc.
DS00002646A-page 3
USB334x
1.0
GENERAL DESCRIPTION
Microchip’s USB334x is a family of Hi-Speed USB 2.0 Transceivers that provide a physical layer (PHY) solution wellsuited for portable electronic devices. Both commercial and industrial temperature applications are supported.
Each model in the USB334x family may use a 60MHz reference clock or the model-number specific reference clock
shown on the Product Identification System page.
Several advanced features make the USB334x the transceiver of choice by reducing both eBOM part count and printed
circuit board (PCB) area. Outstanding ESD robustness eliminates the need for external ESD protection devices in typical applications. The internal Over-Voltage Protection circuit (OVP) protects the USB334x from voltages up to 30V on
the VBUS pin. By using a reference clock from the Link, the USB334x removes the cost of a dedicated crystal reference
from the design. The USB334x includes integrated 3.3V and 1.8V regulators, making it possible to operate the device
from a single power supply.
The USB334x is optimized for use in portable applications where a low operating current and standby currents are
essential. The USB334x operates from a single supply and includes integrated regulators for its supplies. The USB334x
also supports the USB Link Power Management protocol (LPM) to further reduce USB operating currents.
The USB334x family is enabled with RapidCharge Anywhere which supports USB-IF Battery Charging 1.2 for any portable device. RapidCharge Anywhere provides three times the charging current through a USB port over traditional solutions which translate up to 1.5Amps via compatible USB host or dedicated charger. In addition, this provides a complete
USB charging ecosystem between device and host ports such as Dedicated Charging Port (DCP), Charging (CDP) and
Standard (SDP) Downstream Ports. Section 5.9, "USB Charger Detection Support," on page 38 describes this is further
detail.
The USB334x meets all of the electrical requirements for a Hi-Speed USB Host, Device, or an On-the-Go (OTG) transceiver. In addition to the supporting USB signaling, the USB334x also provides USB UART mode and, in versions with
the integrated USB switch, USB Audio mode.
USB334x uses the industry standard UTMI+ Low Pin Interface (ULPI) to connect the USB transceiver to the Link. ULPI
uses a method of in-band signaling and status byte transfers between the Link and PHY to facilitate a USB session with
only twelve pins.
The USB334x uses “wrapper-less” technology to implement the ULPI interface. This “wrapper-less” technology allows
the PHY to achieve a low latency transmit and receive time. Microchip’s low latency transceiver allows an existing UTMI
Link to be reused by adding a UTMI to ULPI bridge. By adding a bridge to the ASIC the existing and proven UTMI Link
IP can be reused.
Versions of the USB334x with the integrated USB switch enable a single USB port of connection.
DS00002646A-page 4
2009-2018 Microchip Technology Inc.
USB334x
FIGURE 1-1:
BLOCK DIAGRAM (USB3341, USB3346, AND USB3347)
REFCLK
OVP
ID
DP
DM
ESD Protection
VBUS
OTG
BC 1.1
Hi-Speed
USB
Transceiver
SPK_L
SPK_R
USB
DP/DM
Switch
Low Jitter
Integrated
PLL
ULPI
Registers
and State
Machine
BIAS
RBIAS
Integrated
Power
Management
RESETB
VBAT
VDD33
VDD18
ULPI
Interface
STP
NXT
DIR
CLKOUT
DATA[7:0]
In USB audio mode, a switch connects the DP pin to the SPK_R pin, and another switch connects he DM pin to the
SPK_L pin. These switches are shown in the lower left-hand corner of .The USB334x can be configured to enter USB
audio mode as described in Section 6.7.2, "USB Audio Mode (USB3341 and USB3346)," on page 61. In addition, these
switches are on when the RESETB pin of the USB334x is asserted. The USB audio mode enables audio signaling from
a single USB port of connection, and the switches may also be used to connect Full Speed USB from another transceiver to the USB connector.
2009-2018 Microchip Technology Inc.
DS00002646A-page 5
USB334x
OVP
ID
DP
ESD Protection
VBUS
DM
OTG
Hi-Speed
USB
Transceiver
XO
BLOCK DIAGRAM (USB3343)
REFCLK / XI
FIGURE 1-2:
Low Jitter
Integrated
PLL
ULPI
Registers
and State
Machine
BIAS
Integrated
Power
Management
RBIAS
RESETB
VBAT
VDD33
VDD18
VDDIO
ULPI
Interface
STP
NXT
DIR
CLKOUT
DATA[7:0]
The USB334x includes an integrated 3.3V LDO regulator that is used to generate 3.3V from power applied to the VBAT
pin. The voltage on the VBAT pin can range from 3.0 to 5.5V. The regulator dropout voltage is less than 100mV which
allows the PHY to continue USB signaling when the voltage on VBAT drops to 3.0V. The USB transceiver will continue
to operate at lower voltages, although some parameters may be outside the limits of the USB specifications. The VBAT
and VDD33 pins should never be connected together.
In USB UART mode, the USB334x DP and DM pins are redefined to enable pass-through of asynchronous serial data.
The USB334x will enter UART mode when programmed, as described in Section 6.7.1, "Entering USB UART Mode,"
on page 60.
1.1
Reference Documents
UTMI+ Low Pin Interface (ULPI) Specification, Revision 1.1
Universal Serial Bus Specification, Revision 2.0
On-The-Go Supplement to the USB 2.0 Specification, Revision 1.3
On-The-Go Supplement to the USB 2.0 Specification, Revision 2.0
USB Battery Charging Specification, Revision 1.2
DS00002646A-page 6
2009-2018 Microchip Technology Inc.
USB334x
2.0
PIN LOCATIONS AND DEFINITIONS
2.1
USB334x Pin Locations and Descriptions
2.1.1
USB3341, USB3346, AND USB3347 PIN DIAGRAM AND PIN DEFINITIONS
The illustration below is viewed from the top of the package.
DIR
STP
VDD18
RESETB
REFCLK
RBIAS
24
23
22
21
20
19
USB3341, USB3346, AND USB3347 PIN LOCATIONS - TOP VIEW
CLKOUT
1
18
ID
NXT
2
17
VBUS
DATA0
3
16
VBAT
DATA1
4
15
VDD33
DATA2
5
14
DM
DATA3
6
13
DP
7
8
9
10
11
12
DATA5
DATA6
DATA7
SPK_L
SPK_R
24Pin QFN
4x4mm
DATA4
FIGURE 2-1:
The following table details the pin definitions for the figure above.
TABLE 2-1:
USB3341, USB3346, AND USB3347 PIN DESCRIPTIONS
Pin
Name
Direction/
Type
Active
Level
1
CLKOUT
Output,
CMOS
N/A
ULPI Clock Output Mode:
60MHz ULPI Clock Outputput. All ULPI signals are
driven synchronous to the rising edge of this clock.
ULPI Clock Input Mode:
Connect this pin to VDD18 to configure 60MHz ULPI
Clock Input mode as described in Section 5.5.1.
2
NXT
Output,
CMOS
High
The PHY asserts NXT to throttle the data. When the
Link is sending data to the PHY, NXT indicates when
the current byte has been accepted by the PHY.
3
DATA[0]
I/O,
CMOS
N/A
ULPI bi-directional data bus. DATA[0] is the LSB.
4
DATA[1]
I/O,
CMOS
N/A
ULPI bi-directional data bus.
2009-2018 Microchip Technology Inc.
Description
DS00002646A-page 7
USB334x
TABLE 2-1:
USB3341, USB3346, AND USB3347 PIN DESCRIPTIONS (CONTINUED)
Pin
Name
Direction/
Type
Active
Level
5
DATA[2]
I/O,
CMOS
N/A
ULPI bi-directional data bus.
6
DATA[3]
I/O,
CMOS
N/A
ULPI bi-directional data bus.
7
DATA[4]
I/O,
CMOS
N/A
ULPI bi-directional data bus.
8
DATA[5]
I/O,
CMOS
N/A
ULPI bi-directional data bus.
9
DATA[6]
I/O,
CMOS
N/A
ULPI bi-directional data bus.
10
DATA[7]
I/O,
CMOS
N/A
ULPI bi-directional data bus. DATA[7] is the MSB.
11
SPK_L
I/O,
Analog
N/A
USB switch in/out for DM signals.
12
SPK_R
I/O,
Analog
N/A
USB switch in/out for DP signals.
13
DP
I/O,
Analog
N/A
D+ pin of the USB cable.
14
DM
I/O,
Analog
N/A
D- pin of the USB cable.
15
VDD33
Power
N/A
3.3V Regulator Output. A 1.0uF ( 3.0V
2.7
3.0
3.3
V
USB UART Mode & UART
RegOutput[1:0] = 10
6V > VBAT > 3.0V
2.47
2.75
3.03
V
USB UART Mode & UART
RegOutput[1:0] = 11
6V > VBAT > 3.0V
2.25
2.5
2.75
V
1.0
3.6V > VDD33 > 2.25V
Units
µF
1.6
1.8
1
Ω
2.0
V
1.0
µF
1
Ω
Piezoelectric Resonator for Internal Oscillator
The internal oscillator may be used with an external quartz crystal or ceramic resonator as described in Section 5.4,
"Crystal Reference Support (USB3343 only)," on page 28. See Table 4-13 for the recommended crystal specifications.
TABLE 4-13:
USB334X QUARTZ CRYSTAL SPECIFICATIONS
Parameter
Symbol
MIN
Crystal Cut
NOM
MAX
Units
Notes
AT, typ
Crystal Oscillation Mode
Fundamental Mode
Crystal Calibration Mode
Parallel Resonant Mode
Frequency
Ffund
Total Allowable PPM Budget
-
See
Example a
on page 79
-
MHz
-
-
±500
PPM
Note 4-9
Shunt Capacitance
CO
-
7 typ
-
pF
Load Capacitance
CL
-
20 typ
-
pF
Drive Level
PW
0.1
-
-
µW
Equivalent Series Resistance
R1
-
-
30
Ω
USB334x REFCLK Pin
Capacitance
-
3 typ
-
pF
Note 4-10
USB334x XO Pin Capacitance
-
3 typ
-
pF
Note 4-10
Note 4-9
The required bit rate accuracy for Hi-Speed USB applications is ±500 ppm as provided in the USB
2.0 Specification. This takes into account the effect of voltage, temperature, aging, etc.
DS00002646A-page 22
2009-2018 Microchip Technology Inc.
USB334x
Note 4-10
4.13
This number includes the pad, the bond wire and the lead frame. Printed Circuit Board (PCB)
capacitance is not included in this value. The PCB capacitance value and the capacitance value of
the XO and REFCLK pins are required to accurately calculate the value of the two external load
capacitors.
ESD and Latch-Up Performance
TABLE 4-14:
Parameter
ESD AND LATCH-UP PERFORMANCE
Conditions
MIN
TYP
MAX
Units
Comments
ESD PERFORMANCE
Note 4-11
Human Body Model
±8
kV
Device
System
EN/IEC 61000-4-2 Contact
Discharge
±25
kV
3rd party system test
System
EN/IEC 61000-4-2 Air-gap
Discharge
±25
kV
3rd party system test
LATCH-UP PERFORMANCE
All Pins
Note 4-11
EIA/JESD 78, Class II
150
mA
REFCLK, XO (USB3343 only), ID, RESETB, SPK_L (USB3341, USB3346, and USB3347 only) and
SPK_R (USB3341, USB3346, and USB3347 only) pins: ±5kV Human Body Model.
2009-2018 Microchip Technology Inc.
DS00002646A-page 23
USB334x
5.0
ARCHITECTURE OVERVIEW
The USB334x consists of the blocks shown in the diagrams below.
FIGURE 5-1:
USB334X SYSTEM DIAGRAM (USB3341, USB3346, AND USB3347)
VDD18
Digital IO
VDD33
DATA7
DATA6
DATA5
DATA4
DATA3
DATA2
DATA1
DATA0
STP
NXT
DIR
CLKOUT
RESETB
HS/FS/LS
TX Encoding
Integrated
Low Jitter
PLL
REFCLK
HS/FS/LS
RX Decoding
BIAS
RID
IdFloat
Rid Value
VDD33
SessValid
RVPD
LDO
ULPI Digitial
VbusValid
Charger
Detection
RPU
VDD33
RPU
RCD
VDD33
RCD
VDD18
ESD Protection
LDO
RVB
VBAT
VDD33
SessEnd
RX Data
RVPU
OVP
VBUS
TX Data
ID
OTG Module
RIDW
IdGnd
TX
DP
RPD
SPK_L
RPD
DM
RX
RBIAS
SPK_R
DS00002646A-page 24
2009-2018 Microchip Technology Inc.
USB334x
FIGURE 5-2:
USB334X SYSTEM DIAGRAM (USB3343)
VDD33
RID
Rid Value
VDD33
SessValid
RVPD
LDO
ULPI Digitial
VbusValid
Charger
Detection
RPU
VDD33
RPU
RCD
VDD33
RCD
VDD18
ESD Protection
LDO
RVB
VBAT
VDD33
SessEnd
VDDIO
DATA7
DATA6
DATA5
DATA4
DATA3
DATA2
DATA1
DATA0
STP
NXT
DIR
CLKOUT
RESETB
RX Data
RVPU
OVP
TX Data
VBUS
Digital IO
IdFloat
ID
OTG Module
RIDW
IdGnd
TX
DP
HS/FS/LS
TX Encoding
Integrated
Low Jitter
PLL
HS/FS/LS
RX Decoding
BIAS
REFCLK / XI
XO
5.1
RPD
RPD
DM
RX
RBIAS
ULPI Digital Operation and Interface
This section of the USB334x is covered in detail in Section 6.0, "ULPI Operation".
5.2
USB 2.0 Hi-Speed Transceiver
The blocks in the lower left-hand corner of interface to the DP/DM pins.
5.2.1
USB TRANSCEIVER
The USB334x transceiver includes a Universal Serial Bus Specification Rev 2.0 compliant receiver and transmitter. The
DP/DM signals in the USB cable connect directly to the receivers and transmitters.
The receiver consists of receivers for HS and FS/LS mode. Depending on the mode, the selected receiver provides the
serial data stream through the multiplexer to the RX Logic block. For HS mode support, the HS RX block contains a
squelch circuit to insure that noise is not interpreted as data. The RX block also includes a single-ended receiver on
each of the data lines to determine the correct FS linestate.
Data from the Link is encoded, bit stuffed, serialized and transmitted onto the USB cable by the transmitter. Separate
differential FS/LS and HS transmitters are included to support all modes.
The USB334x TX block meets the HS signaling level requirements in the USB 2.0 Specification when the PCB traces
from the DP and DM pins to the USB connector are correctly designed. In some systems the proper 90Ω differential
impedance can not be maintained and it may be desirable to compensate for loss by adjusting the HS transmitter amplitude and this HS squelch threshold. The PHYBoost bits in the HS Compensation Register may be configured to adjust
the HS transmitter amplitude at the DP and DM pins. The VariSense bits in the HS Compensation Register can also be
used to lower the squelch threshold to compensate for losses on the PCB.
To ensure proper operation of the USB transceiver the settings of Table 5-1 must be followed.
2009-2018 Microchip Technology Inc.
DS00002646A-page 25
USB334x
5.2.2
TERMINATION RESISTORS
The USB334x transceiver fully integrates all of the USB termination resistors on both DP and DM. This includes 1.5kΩ
pull-up resistors, 15kΩ pull-down resistors and the 45Ω High Speed termination resistors. These resistors require no
tuning or trimming by the Link. The state of the resistors is determined by the operating mode of the transceiver when
operating in synchronous mode.
The XcvrSelect[1:0], TermSelect and OpMode[1:0] bits in the Function Control register, and the DpPulldown and
DmPulldown bits in the OTG Control register control the configuration of the termination resistors. All possible valid
resistor combinations are shown in Table 5-1, and operation is supported in only the configurations shown. If a ULPI
Register Setting is configured that does not match a setting in the table, the transceiver operation is not maintained and
the settings in the last row of Table 5-1 will be used.
•
•
•
•
•
RPU_DP_EN activates the 1.5kΩ DP pull-up resistor
RPU_DM_EN activates the 1.5kΩ DM pull-up resistor
RPD_DP_EN activates the 15kΩ DP pull-down resistor
RPD_DM_EN activates the 15kΩ DM pull-down resistor
HSTERM_EN activates the 45Ω DP and DM High Speed termination resistors
TABLE 5-1:
DP/DM TERMINATION VS. SIGNALING MODE
USB334x Termination
Resistor Settings
RPU_DM_EN
RPD_DP_EN
RPD_DM_EN
HSTERM_EN
01b
Xb
Xb
0b
0b
0b
0b
0b
Power-up or VBUS < VSESSEND
01b
0b
00b
1b
1b
0b
0b
1b
1b
0b
Host Chirp
00b
0b
10b
1b
1b
0b
0b
1b
1b
1b
Host High Speed
00b
0b
00b
1b
1b
0b
0b
1b
1b
1b
Host Full Speed
X1b
1b
00b
1b
1b
0b
0b
1b
1b
0b
Host HS/FS Suspend
01b
1b
00b
1b
1b
0b
0b
1b
1b
0b
Host HS/FS Resume
01b
1b
10b
1b
1b
0b
0b
1b
1b
0b
Host Low Speed
10b
1b
00b
1b
1b
0b
0b
1b
1b
0b
Host LS Suspend
10b
1b
00b
1b
1b
0b
0b
1b
1b
0b
Host LS Resume
10b
1b
10b
1b
1b
0b
0b
1b
1b
0b
Host Test J/Test_K
00b
0b
10b
1b
1b
0b
0b
1b
1b
1b
Peripheral Chirp
00b
1b
10b
0b
0b
1b
0b
0b
0b
0b
Peripheral HS
00b
0b
00b
0b
0b
0b
0b
0b
0b
1b
Peripheral FS
01b
1b
00b
0b
0b
1b
0b
0b
0b
0b
DmPulldown
Xb
DpPulldown
XXb
OpMode[1:0]
Tri-State Drivers, Note 5-1
Signaling Mode
TermSelect
RPU_DP_EN
XcvrSelect[1:0]
ULPI Register Settings
General Settings
Host Settings
Peripheral Settings
DS00002646A-page 26
2009-2018 Microchip Technology Inc.
USB334x
TABLE 5-1:
DP/DM TERMINATION VS. SIGNALING MODE (CONTINUED)
USB334x Termination
Resistor Settings
RPU_DM_EN
RPD_DP_EN
RPD_DM_EN
HSTERM_EN
00b
0b
0b
1b
0b
0b
0b
0b
Peripheral HS/FS Resume
01b
1b
10b
0b
0b
1b
0b
0b
0b
0b
Peripheral LS
10b
1b
00b
0b
0b
0b
1b
0b
0b
0b
Peripheral LS Suspend
10b
1b
00b
0b
0b
0b
1b
0b
0b
0b
Peripheral LS Resume
10b
1b
10b
0b
0b
0b
1b
0b
0b
0b
Peripheral Test J/Test K
00b
0b
10b
0b
0b
0b
0b
0b
0b
1b
OTG device, Peripheral Chirp
00b
1b
10b
0b
1b
1b
0b
0b
1b
0b
OTG device, Peripheral HS
00b
0b
00b
0b
1b
0b
0b
0b
1b
1b
OTG device, Peripheral FS
01b
1b
00b
0b
1b
1b
0b
0b
1b
0b
OTG device, Peripheral HS/FS Suspend
01b
1b
00b
0b
1b
1b
0b
0b
1b
0b
OTG device, Peripheral HS/FS Resume
01b
1b
10b
0b
1b
1b
0b
0b
1b
0b
OTG device, Peripheral Test J/Test K
00b
0b
10b
0b
1b
0b
0b
0b
1b
1b
01b
0b
00b
0b
1b
0b
0b
0b
1b
0b
0b
0b
1b
1b
0b
DmPulldown
1b
DpPulldown
01b
OpMode[1:0]
Peripheral HS/FS Suspend
Signaling Mode
TermSelect
RPU_DP_EN
XcvrSelect[1:0]
ULPI Register Settings
Charger Detection
Connect Detect
Any combination not defined above,
Note 5-2
Note:
• This is equivalent to Table 40, Section 4.4 of the ULPI 1.1 specification.
• USB334x does not support operation as an upstream hub port. See Section 6.4.1.3, "UTMI+ Level 3," on
page 53.
Note 5-1
When RESETB = 0 The HS termination will tri-state the USB drivers
Note 5-2
The transceiver operation is not maintained in a combination that is not defined.
The USB334x uses the 27% resistor ECN resistor tolerances. The resistor values are shown in Table 4-6.
5.3
Bias Generator
This block consists of an internal bandgap reference circuit used for generating the driver current and the biasing of the
analog circuits. This block requires an external 8.06KΩ,1% tolerance, reference resistor connected from RBIAS to
ground. This resistor should be placed as close as possible to the USB334x to minimize the trace length. The nominal
voltage at RBIAS is 0.8V +/- 10% and therefore the resistor will dissipate approximately 80 µW of power.
2009-2018 Microchip Technology Inc.
DS00002646A-page 27
USB334x
5.4
Crystal Reference Support (USB3343 only)
The USB3343 provide support for a 26 MHz crystal to provide the reference frequency required by the device in place
of a clock oscillator. The crystal should be connected to the REFCLK/XI and XO pins as shown in Figure 8-2. If a 26 MHz
clock oscillator is used in place of a crystal, it should be driven into the REFCLK/XI pin, and the XO pin should be left
floating.
Proper care should be taken to ensure that a crystal is selected with appropriate power dissipation characteristics.
5.5
Integrated Low Jitter PLL
The USB334x uses an integrated low jitter phase locked loop (PLL) to provide a clean 480 MHz clock required for HS
USB signal quality. This clock is used by the PHY during both transmit and receive. The USB334x PLL requires an accurate frequency reference to be driven on the REFCLK pin.
5.5.1
REFCLK FREQUENCY SELECTION
The USB334x PLL is designed to operate in one of two reference clock modes. In the first mode, the 60 MHz ULPI clock
is driven on the REFCLK pin. In the second mode a reference clock is driven on the REFCLK pin. The Link is driving
the ULPI clock, in the first mode, and this is referred to as ULPI Clock Input Mode. In the second mode, the USB334x
generates the ULPI clock, and this is referred to as ULPI Clock Output Mode.
During start-up, the USB334x monitors the CLKOUT pin. If a connection to VDD18 (USB3341, USB3346, and
USB3347) or VDDIO (USB3343) is detected, the USB334x is configured for a 60 MHz ULPI reference clock driven on
the REFCLK pin. Section 5.5.1.1, "ULPI Clock Input Mode (60 MHz REFCLK Mode)," on page 28 and Section 5.5.1.2,
"ULPI Clock Output Mode," on page 29 describe how to configure the USB334x for either ULPI Clock Input Mode or
ULPI Clock Output Mode.
5.5.1.1
ULPI Clock Input Mode (60 MHz REFCLK Mode)
When using ULPI Clock Input Mode, the Link must supply the 60 MHz ULPI clock to the USB334x. In this mode the
60 MHz ULPI Clock is connected to the REFCLK pin, and the CLKOUT pin is tied high to VDD18 (USB3341, USB3346,
and USB3347) or VDDIO(USB3343).
After the PLL has locked to the correct frequency, the USB334x will de-assert DIR and the Link can begin using the
ULPI interface. The USB334x will start the clock within the time specified in Table 4-3. For Host applications, the ULPI
AutoResume bit should be enabled. This is described in Section 6.4.1.4, "Host Resume K," on page 53.
FIGURE 5-3:
CONFIGURING THE USB334X FOR ULPI CLOCK INPUT MODE (60 MHZ)
VDD18/
VDDIO
~~
CLKOUT
ULPI Clk Out
REFCLK
To PLL
Link
Reference Clk In
DS00002646A-page 28
~~
Clock
Source
SMSC PHY
2009-2018 Microchip Technology Inc.
USB334x
5.5.1.2
ULPI Clock Output Mode
When using ULPI Clock Output Mode, the USB334x generates the 60 MHz ULPI clock used by the Link. In this mode,
the REFCLK pin must be driven with the model-specific frequency, and the CLKOUT pin sources the 60 MHz ULPI
clock to the Link. When using ULPI Clock Output Mode, the system must not drive the CLKOUT pin following POR or
hardware reset with a voltage that exceeds the value of VIH_ED provided in Table 4-4. An example of ULPI Clock Output
Mode is shown in Figure 8-1
After the PLL has locked to the correct frequency, the USB334x generates the 60 MHz ULPI clock on the CLKOUT pin,
and de-asserts DIR to indicate that the PLL is locked. The USB334x will start the clock within the time specified in
Table 4-3, and it will be accurate to within ±500ppm. For Host applications the ULPI AutoResume bit should be enabled.
This is described in Section 6.4.1.4, "Host Resume K," on page 53.
When using ULPI Clock Output Mode, the edges of the reference clock do not need to be aligned in any way to the ULPI
interface signals. There is no need to align the phase of the REFCLK and the CLKOUT.
For the USB3341, USB3343, USB3346, and USB3347, the reference clock frequency required is shown in the Product
Identification System section.
FIGURE 5-4:
CONFIGURING THE USB334X FOR ULPI CLOCK OUTPUT MODE
~~
ULPI Clk In
CLKOUT
From PLL
Link
Clock
Source
REFCLK
To PLL
~~
5.5.2
MCHP PHY
REFCLK AMPLITUDE
The reference clock should be connected to the REFCLK pin as shown in the application diagrams, . The REFCLK pin
is designed to be driven with a square wave from 0V to VDD18 (USB3341, USB3346, and USB3347) or VDDIO
(USB3343), but can be driven with a square wave from 0V to as high as 3.6V. The USB334x uses only the positive edge
of the REFCLK.
If a digital reference is not available, the REFCLK pin can be driven by an analog sine wave that is AC coupled into the
REFCLK pin. If using an analog clock the DC bias should be set at the mid-point of the VDD18 supply using a bias
circuit as shown in Figure 5-5. The amplitude must be greater than 300mV peak to peak. The component values provided in Figure 5-5 are for example only. The actual values should be selected to satisfy system requirements.
The REFCLK amplitude must comply with the signal amplitudes shown in Table 4-5 and the duty cycle in Table 4-3.
2009-2018 Microchip Technology Inc.
DS00002646A-page 29
USB334x
FIGURE 5-5:
EXAMPLE OF CIRCUIT USED TO SHIFT A REFERENCE CLOCK COMMONMODE VOLTAGE LEVEL
47k
1.8V Supply
To REFCLK pin
0.1uF
5.5.3
47k
Clock
REFCLK JITTER
The USB334x is tolerant to jitter on the reference clock. The REFCLK jitter should be limited to a peak to peak jitter of
less than 1nS over a 10uS time interval. If this level of jitter is exceeded when configured for either ULPI Clock Input
Mode or ULPI Clock Output Mode, the USB334x High Speed eye diagram may be degraded.
The frequency accuracy of the REFCLK must meet the +/- 500ppm requirement as shown in Table 4-3.
5.5.4
REFCLK ENABLE/DISABLE
The REFCLK should be enabled when the RESETB pin is brought high. The ULPI interface will start running after the
time specified in Table 4-3. If the reference clock enable is delayed relative to the RESETB pin, the ULPI interface will
start operation delayed by the same amount. The reference clock can be run at anytime the RESETB pin is low without
causing the USB334x to start-up or draw current.
When the USB334x is placed in Low Power Mode or Carkit Mode, the reference clock can be stopped after the final
ULPI register write is complete. The STP pin is asserted to bring the USB334x out of Low Power Mode. The reference
clock should be started at the same time STP is asserted to minimize the USB334x start-up time.
If the reference clock is stopped while in ULPI Synchronous mode the PLL will come out of lock and the frequency of
oscillation will decrease to the minimum allowed by the PLL design. If the reference clock is stopped during a USB session, the session may drop.
5.6
Internal Regulators and POR
The USB334x includes integrated power management functions, including a Low-Dropout regulator that can be used
to generate the 3.3V USB supply, an integrated 1.8V regulator, and a POR generator described in Section 5.6.2, "Power
On Reset (POR)," on page 31.
5.6.1
INTEGRATED LOW DROPOUT REGULATORS
The USB334x includes two integrated linear regulators. Power sourced at the VBAT pin is regulated to 3.3V and 1.8V
output on the VDD33 and VDD18 pins. To ensure stability, both regulators require an external bypass capacitor as specified in Table 4-12 placed as close to the pin as possible.
The USB334x regulators are designed to generate the 3.3 Volt and 1.8 Volt supplies for the USB334x only. Using the
regulators to provide current for other circuits is not recommended and Microchip does not ensure USB performance or
regulator stability.
During USB UART mode the 3.3V regulator output voltage can be changed to allow the USB334x to work with UARTs
operating at different operating voltages. The 3.3V regulator output is configured to the voltages shown in Table 4-12
with the UART RegOutput[1:0] bits in the USB IO & Power Management register.
The regulators are enabled by the RESETB pin. When RESETB pin is low both regulators are disabled and the regulator
outputs are pulled low by weak pull-down. The RESETB pin must be brought high to enable the regulators.
DS00002646A-page 30
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USB334x
For peripheral-only or host-only bus-powered applications, the input to VBAT may be derived from the VBUS pin of the
USB connector. In this configuration, the supply must be capable of withstanding any transient voltage present at the
VBUS pin of the USB connector. Microchip does not recommend connecting the VBAT pin to the VBUS terminal of the
USB connector.
5.6.2
POWER ON RESET (POR)
The USB334x provides a POR circuit that generates an internal reset pulse after the VDD18 supply is stable. After the
internal POR goes high the USB334x will release from reset and begin normal ULPI operation as described in Note 5-3.
The ULPI registers will power up in their default state summarized in Table 7-1 when the 1.8V supply comes up. Cycling
the RESETB pin can also be used to reset the ULPI registers to their default state (and reset all internal state machines)
by bringing the pin low for a minimum of 1 microsecond and then high. It is not necessary to wait for the VDD33 and
VDD18 pins to discharge to 0 volts to reset the part.
The RESETB pin must be pulled high to enable the 3.3V and 1.8V regulators. A pull-down resistor is not present on the
RESETB pin and therefore the system should drive the RESETB pin to the desired state at all times. If the system does
not need to place the USB334x into reset mode the RESETB pin can be connected to a supply between 1.8V and 3.3V.
5.6.3
RECOMMENDED POWER SUPPLY SEQUENCE
For USB operation, the USB334x requires a valid voltage on the VBAT and VDDIO pins. The VDD33 and VDD18 regulators are automatically enabled when the RESETB pin is brought high. Table 5-2 presents the power supply configurations in more detail.
The RESETB pin can be held low until the VBAT supply is stable. If the Link is not ready to interface the USB334x, the
Link may choose to hold the RESETB pin low until it is ready to control the ULPI interface.
TABLE 5-2:
OPERATING MODE VS. POWER SUPPLY CONFIGURATION
VBAT
VDDIO
(Note 5-4)
RESETB
0
0
0
Powered Off
1
X
0
RESET Mode. (Note 5-3)
1
1
1
Full USB operation as described in Section 6.0, "ULPI
Operation," on page 42.
Operating Modes Available
Note 5-3
VDDIO must be present for ULPI pins to tri-state.
Note 5-4
USB3343 only.
5.6.4
START-UP
The power on default state of the USB334x is ULPI Synchronous mode. The USB334x requires the following conditions
to begin operation: the power supplies must be stable, the REFCLK must be present and the RESETB pin must be high.
After these conditions are met, the USB334x will begin ULPI operation that is described in Section 6.0, "ULPI Operation," on page 42.
Figure 5-6 below shows a timing diagram to illustrate the start-up of the USB334x. At T0, the supplies are stable and
the USB334x is held in reset mode. At T1, the Link drives RESETB high after the REFCLK has started. The RESETB
pin may be brought high asynchronously to REFCLK. Once, the 3.3V and 1.8V internal supplies become stable the
USB334x will apply the 15 KΩ pull downs to the data bus and assert DIR until the internal PLL has locked. After the PLL
has locked, the USB334x will check that the Link has de-asserted STP and at T2 it will de-assert DIR and begin ULPI
operation.
The ULPI bus will be available as shown in Figure 5-6 in the time defined as TSTART given in Table 4-3. If the REFCLK
signal starts after the RESETB pin is brought high, then time T0 will begin when REFCLK starts. TSTART also assumes
that the Link has de-asserted STP. If the Link has held STP high the USB334x will hold DIR high until STP is deasserted. When the LINK de-asserts STP, it must be ready drive the ULPI data bus to idle (00h) for a minimum of one
clock cycle after DIR de-asserts.
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DS00002646A-page 31
USB334x
FIGURE 5-6:
ULPI START-UP TIMING
T0
SUPPLIES
STABLE
T1
REFCLK
T2
REFCLK valid
RESETB
DATA[7:0]
PHY Tri-States
PHY Drives Idle
DIR
PHY Tri-States
PHY Drives High
STP
IDLE
RXCMD
IDLE
LINK Drives Low
TSTART
5.7
USB On-The-Go (OTG)
The USB334x provides support for the USB OTG protocol. OTG allows the USB334x to be dynamically configured as
a host or peripheral depending on the type of cable inserted into the Micro-AB receptacle. When the Micro-A plug of a
cable is inserted into the Micro-AB receptacle, the USB device becomes the A-device. When a Micro-B plug is inserted,
the device becomes the B-device. The OTG A-device behaves similar to a Host while the B-device behaves similar to
a peripheral. The differences are covered in the “On-The-Go Supplement to the USB 2.0 Specification”. In applications
where only USB Host or USB Peripheral is required, the OTG Module is unused.
5.7.1
ID RESISTOR DETECTION
The ID pin of the USB connector is monitored by the ID pin of the USB334x to detect the attachment of different types
of USB devices and cables. For device only applications that do not use the ID signal the ID pin should be connected
to VDD33. The block diagram of the ID detection circuitry is shown in Figure 5-7 and the related parameters are given
in Table 4-9.
DS00002646A-page 32
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USB334x
FIGURE 5-7:
USB334X ID RESISTOR DETECTION CIRCUITRY
~~
VDD33
ID
RID=100K
RIDW>1M
IdPullup
To USB Con.
IdGnd
Vref IdGnd
en
IdGndDrv
IdFloat
Vref IdFloat
en
Rid ADC
~~
5.7.1.1
IdGnd Rise or
IdGnd Fall
IdFloatRise or
IdFloatFall
RidValue
OTG Module
USB OTG Operation
The USB334x can detect ID grounded and ID floating to determine if an A or B cable has been inserted. The A plug will
ground the ID pin while the B plug will float the ID pin. These are the only two valid states allowed in the OTG Protocol.
To monitor the status of the ID pin, the Link activates the IdPullup bit in the OTG Control register, waits 50mS and then
reads the status of the IdGnd bit in the USB Interrupt Status register. If an A cable has been inserted the IdGnd bit will
read 0. If a B cable is inserted, the ID pin is floating and the IdGnd bit will read 1.
The USB334x provides an integrated weak pull-up resistor on the ID pin, RIDW. This resistor is present to keep the ID
pin in a known state when the IdPullup bit is disabled and the ID pin is floated. In addition to keeping the ID pin in a
known state, it enables the USB334x to generate an interrupt to inform the link when a cable with a resistor to ground
has been attached to the ID pin. The weak pull-up is small enough that the largest valid RID resistor pulls the ID pin low
and causes the IdGnd comparator to go low.
After the link has detected an ID pin state change, the RID converter can be used to determine the resistor value as
described in Section 5.7.1.2, "Measuring ID Resistance to Ground," on page 33.
5.7.1.2
Measuring ID Resistance to Ground
The Link can use the integrated resistance measurement capabilities of the USB334x to determine the value of an ID
resistance to ground. The following table details the valid values of resistance to ground that the USB334x can detect.
2009-2018 Microchip Technology Inc.
DS00002646A-page 33
USB334x
TABLE 5-3:
Note:
VALID VALUES OF ID RESISTANCE TO GROUND
ID Resistance to Ground
Rid Value
Ground
000
75Ω +/-1%
001
102kΩ +/-1%
010
200kΩ+/-1%
011
Floating
101
IdPullUp = 0
The ID resistance to ground can be read while the USB334x is in Synchronous Mode. When a resistor to ground is
attached to the ID pin, the state of the IdGnd comparator will change. After the Link has detected ID transition to ground,
it can use the methods described in Section 6.8, "RID Converter Operation," on page 61 to operate the Rid converter.
5.7.1.3
Note:
Using IdFloat Comparator (not recommended)
The ULPI specification details a method to detect a 102 kΩ resistance to ground using the IdFloat comparator. This method can only detect 0Ω, 102 kΩ, and floating terminations of the ID pin. Due to this limitation
it is recommended to use the RID Converter as described in Section 5.7.1.2, "Measuring ID Resistance to
Ground," on page 33.
The ID pin can be either grounded, floated, or connected to ground with a 102 kΩ external resistor. To detect the 102K
resistor, set the idPullup bit in the OTG Control register, causing the USB334x to apply the 100K internal pull-up connected between the ID pin and VDD33. Set the idFloatRise and idFloatFall bits in the Carkit Interrupt Enable register to
enable the IdFloat comparator to generate an RXCMD to the Link when the state of the IdFloat changes. As described
in Figure 6-3, the alt_int bit of the RXCMD will be set. The values of IdGnd and IdFloat are shown for the three types
cables that can attach to the USB Connector in Table 5-4.
TABLE 5-4:
Note:
IDGND AND IDFLOAT VS. ID RESISTANCE TO GROUND
ID Resistance
IDGND
IDFLOAT
Float
1
1
102K
1
0
GND
0
0
The ULPI register bits IdPullUp, IdFloatRise, and IdFloatFall should be enabled.
To save current when an A Plug is inserted, the internal 102kΩ pull-up resistor can be disabled by clearing the IdPullUp
bit in the OTG Control register and the IdFloatRise and IdFloatFall bits in both the USB Interrupt Enable Rising and USB
Interrupt Enable Falling registers. If the cable is removed the weak RIDW will pull the ID pin high.
The IdGnd value can be read using the ULPI USB Interrupt Status register, bit 4. In host mode, it can be set to generate
an interrupt when IdGnd changes by setting the appropriate bits in the USB Interrupt Enable Rising and USB Interrupt
Enable Falling registers. The IdFloat value can be read by reading the ULPI Carkit Interrupt Status register bit 0.
DS00002646A-page 34
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USB334x
Note:
5.7.2
The IdGnd switch has been provided to ground the ID pin for future applications.
VBUS MONITORING AND VBUS PULSING
The USB334x includes all of the VBUS comparators required for OTG. The VBUSVld, SessVld, and SessEnd comparators shown in Figure 5-8 are fully integrated into the USB334x. These comparators are used to monitor changes in the
VBUS voltage, and the state of each comparator can be read from the USB Interrupt Status register.
The VbusVld comparator is used by the Link, when configured as an A device, to ensure that the VBUS voltage on the
cable is valid. The SessVld comparator is used by the Link when configured as both an A or B device to indicate a session is requested or valid. Finally the SessEnd comparator is used by the B-device to indicate a USB session has ended.
Also included in the VBUS Monitor and Pulsing block are the resistors used for VBUS pulsing in SRP. The resistors used
for VBUS pulsing include a pull-down to ground and a pull-up to VDD33.
In some applications, voltages much greater than 5.5V may be present at the VBUS pin of the USB connector. The
USB334x includes an over voltage protection circuit that protects the VBUS pin of the USB334x from excessive voltages
as shown in Figure 5-8.
FIGURE 5-8:
USB334X OTG VBUS BLOCK
~~
VDD33
ChrgVbus
0.5V
SessEnd
RVPU
en
RVPD
RVBUS
1.4V
RVB
To USB Con.
SessValid
VBUS
Overvoltage
Protection
VBUS
SessEnd Rise or
SessEnd Fall
VbusValid
4.575V
DischrgVbus
en
VbusValid Rise or
VbusValid Fall
[0, X]
[1, 0]
EXTVBUS (logic 1)
IndicatorComplement
RXCMD VbusValid
[1, 1]
[UseExternalVbusindicator, IndicatorPassThru]
~~
5.7.2.1
MCHP PHY
SessEnd Comparator
The SessEnd comparator is used during the Session Request Protocol (SRP). The comparator is used by the B-device
to detect when a USB session has ended and it is safe to start Vbus Pulsing to request a USB session from the A-device.
When VBUS goes below the threshold in Table 4-8, the USB session is considered to be ended, and SessEnd will transition from 0 to 1. The SessEnd comparator can be disabled by clearing this bit in both the USB Interrupt Enable Rising
and USB Interrupt Enable Falling registers. When disabled, the SessEnd bit in the USB Interrupt Status register will read
0.
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DS00002646A-page 35
USB334x
The SessEnd Comparator is only used when configured as an OTG device. If the USB334x is used as a Host or Device
only the SessEnd Comparator should be disabled, using the method described above.
5.7.2.2
SessVld Comparator
The SessVld comparator is used when the PHY is configured as both an A and B device. When configured as an A
device, the SessVld is used to detect Session Request protocol (SRP). When configured as a B device, SessVld is used
to detect the presence of VBUS. The SessVld comparator output can also be read from the USB Interrupt Status register. The SessVld comparator will also generate an RX CMD, as detailed in Section 6.3.1, "ULPI Receive Command (RX
CMD)," on page 48, anytime the comparator changes state. The SessVld interrupts can be disabled by clearing this bit
in both the USB Interrupt Enable Rising and USB Interrupt Enable Falling registers. When the interrupts are disabled,
the SessVld comparator is still operational and will generate RX CMD’s. The SessVld comparator trip point is detailed
in Table 4-9.
Note:
The OTG Supplement specifies a voltage range for A-Device Session Valid and B-Device Session Valid
comparator. The USB334x PHY combines the two comparators into one and uses the narrower threshold
range.
5.7.2.3
VbusVld Comparator
The VbusVld comparator is only used when the USB334x is configured as a host that can supply less than 100mA VBUS
current. In the USB protocol, the A-device supplies the VBUS voltage and is responsible to ensure it remains within a
specified voltage range. The VbusVld comparator can be disabled by clearing this bit in both the USB Interrupt Enable
Rising and USB Interrupt Enable Falling registers. When disabled, bit 1 of the USB Interrupt Status register will return
a 0. The VbusVld comparator threshold values are detailed in Table 4-9.
If the USB334x is used as a Device only the VbusValid Comparator should be disabled, using the method described
above.
The USB334x includes the external VbusVld indicator logic as detailed in the ULPI Specification. The external VbusVld
indicator is tied to a logic one. The decoding of this logic is shown in Table 5-5 below. By default this logic is disabled.
TABLE 5-5:
EXTERNAL VBUS INDICATOR LOGIC
Typical
Application
Use External
Vbus
Indicator
Indicator
Pass Thru
Indicator
Complement
OTG Device
0
X
X
Internal VbusVld comparator (Default)
1
1
0
Fixed 1
1
1
1
Fixed 0
1
0
0
Internal VbusVld comparator.
1
0
1
Fixed 0
1
1
0
Fixed 1
1
1
1
Fixed 0
0
X
X
Internal VbusVld comparator. This
information should not be used by the
Link. (Note 5-5)
Standard Host
Standard
Peripheral
Note 5-5
RXCMD Vbus Valid
Encoding Source
A peripheral should not use VbusVld to begin operation. The peripheral should use SessVld to detect
the presence of VBUS on the USB connector. VbusVld should only be used for USB Host and OTG
A-device applications.
DS00002646A-page 36
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USB334x
5.7.2.4
VBUS Pulsing with Pull-up and Pull-down Resistors
In addition to the internal VBUS comparators, the USB334x also includes the integrated VBUS pull-up and pull-down
resistors used for VBUS Pulsing during OTG Session Request Protocol. To discharge the VBUS voltage so that a Session Request can begin, the USB334x provides a pull-down resistor from VBUS to GND. This resistor is controlled by
the DischargeVbus bit 3 of the OTG Control register. The pull-up resistor is connected between VBUS and VDD33. This
resistor is used to pull VBUS above 2.1 volts so that the A-Device knows that a USB session has been requested. The
state of the pull-up resistor is controlled by the bit 4 ChargeVbus of the OTG Control register. The Pull-Up and Pull-Down
resistor values are detailed in Table 4-9.
The internal VBUS Pull-up and Pull-down resistors are designed to include the RVBUS external resistor in series. This
external resistor is used by the VBUS Over voltage protection described below.
5.7.2.5
VBUS Input Impedance
The OTG Supplement requires an A-Device that supports Session Request Protocol to have a VBUS input impedance
less than 100kΩ and greater the 40kΩ to ground. The USB334x provides a 75kΩ resistance to ground, RVB. The RVB
resistor tolerance is detailed in Table 4-9.
5.7.2.6
VBUS Over Voltage Protection (OVP)
The USB334x provides an integrated over voltage protection circuit to protect the VBUS pin from excessive voltages
that may be present at the USB connector. The over voltage protection circuit works with an external resistor (RVBUS)
by drawing current across the resistor to reduce the voltage at the VBUS pin.
When voltage at the VBUS pin exceeds 5.5V, the Over voltage Protection block will sink current to ground until VBUS
is below 5.5V. The current drops the excess voltage across RVBUS and protects the USB334x VBUS pin. The required
RVBUS value is dependent on the operating mode of the USB334x as shown in Table 5-6.
TABLE 5-6:
REQUIRED RVBUS RESISTOR VALUE
Operating Mode
RVBUS
Device only
20kΩ ±5%
OTG Host Capable of less than 100mA of current on VBUS
1kΩ ±5%
Host or OTG Host capable of >100mA
UseExternalVbusIndicator = 1
20kΩ ±5%
The Over voltage Protection circuit is designed to protect the USB334x from continuous voltages up to 30V on the
RVBUS resistor.
The RVBUS resistor must be sized to handle the power dissipated across the resistor. The resistor power can be found
using the equation below:
2
Vprotect – 5.0
P RVBUS = -------------------------------------------R VBUS
Where:
• Vprotect is the VBUS protection required.
• RVBUS is the resistor value, 1kΩ or 20kΩ.
• PRVBUS is the required power rating of RVBUS.
For example, protecting a peripheral or device only application to 15V would require a 20kΩ RVBUS resistor with a power
rating of 0.05W. To protect an OTG product to 15V would require a 1kΩ RVBUS resistor with a power rating of 0.1W.
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USB334x
5.7.3
DRIVING EXTERNAL VBUS
The USB334x monitors VBUS as described in VBUS Monitoring and VBUS Pulsing. The USB334x does not provide an
external output for the DrvVbusExternal ULPI register. For OTG and Host applications, the external VBUS supply or
power switch must be controlled by the Link.
5.8
USB UART Support
The USB334x provides support for the USB UART interface as detailed in the ULPI specification and the former CEA936A specification. The USB334x can be placed in UART Mode using the method described in Section 6.7, "Carkit
Mode," on page 59, and the regulator output will automatically switch to the value configured by the UART RegOutput
bits in the USB IO & Power Management register. While in UART mode, the Linestate signals cannot be monitored on
the DATA[0] and DATA[1] pins.
5.9
USB Charger Detection Support
The following blocks allow the USB334x to detect when a Battery Charger, Charging Host Port, or a USB Host is
attached to the USB connector. The USB334x can also be configured to appear as a Charging Host Port, all according
to the USB-IF Battery Charging 1.2 specification. The charger detection circuitry should be disabled during USB operation.
FIGURE 5-9:
USB CHARGER DETECTION BLOCK DIAGRAM
~~
VDD33
C hargerP ullupE nD P
RCD
RCD
C hargerP ullupE nD M
C ontactD etectE n
en
I D P _S R C
DP
V D A T_S R C
T o U S B C on .
V D atS rcE n
H ostC hrgE n
DM
V D A T_R E F
RPD
RPD
T o U S B C on .
V datD et
en
ID atS inkE n
en
I D A T_S IN K
D pP ulldow n
D m P ulldow n
~~
Note:
MCHP PHY
The italic names in the Figure 5-9 correspond to bits in the ULPI register set.
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USB334x
The charger detection circuitry runs from the VDD33 supply and requires that the VDD33 supply to be present to run
the charger detection circuitry. The VDD33 supply is present anytime the RESETB pin is pulled high and VBAT is present. The charger detection circuits are fully functional while in Low Power Mode (Suspendm = 0). The status of the VdatDet can be relayed back to the Link through the ULPI interrupts in both Synchronous mode and Low Power Mode.
5.9.1
ACTIVE ANALOG CHARGER DETECTION (USB-IF BATTERY CHARGING 1.2)
The USB334x includes the active analog charger detection specified in the USB-IF Battery Charging Specification. The
additional analog circuitry will allow the USB334x to:
1.
2.
3.
4.
Detect a Dedicated Charging Port (DCP) with the DP and DM pins shorted together.
Detect a Standard Downstream Port (SDP) which has no battery charging circuitry.
Detect a Charging Downstream Port (CDP) which actively supplies voltage to the DM pin when connected to a
USB-IF BC 1.2 compatible device.
Behave as a Charging Downstream Port by enabling the voltage source on the DM pin.
The charger detection circuitry is shown in Figure 5-9.
The VdatDet output is qualified with the Linestate[1:0] value. If the Linestate is not equal to 00 the VdatDet signal will
not assert.
The proper detection process flows through different modes of detection and uses the linestate and VdatDet signals
values to determine the connection. Table 5-7 describes the bit values that need to be set to enter each mode.
DMPULLDOWN
DPPULLDOWN
HOSTCHRGEN
CONTACTDETE
N
Charger Detection Modes
IDATSINKEN
USB CHARGER SETTING VS. MODES
VDATSRCEN
TABLE 5-7:
Device Connect Detect
(The Connect Detect setting in Table 5-1 must be followed)
0
0
1
0
0
1
Device Charger Detection
1
1
0
0
0
0
Device Enhanced Charger Detection
1
1
0
1
0
0
Device USB Operation
0
0
0
0
0
0
Charging Host Port, no charging device attached and SE0
(VdatDet = 0)
0
1
0
1
1
1
Charging Host Port, charging device attached (VdatDet = 1)
1
1
0
1
1
1
Charging Host Port USB Operation
0
0
0
1
1
1
5.9.1.1
Example Charger Detection Flow - Dedicated Charging Port
The USB-IF Battery Charging 1.2 specification describes in detail the flow for each charger type, but below is an example of the flow used to detect a Dedicated Charger (DCP).
1.
2.
Device detects Vbus voltage is present from RXCMD, (SESS_VLD is 1)
Device enters the Device Connect Detect mode.
If the linestate still equals 10 after a specified timeout, the charger is an unknown charger and there will be no
attempted USB enumeration.
If the linestate equals 00 or 11, the device will go to the next mode:
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USB334x
3.
Device enters Device Charger Detection mode.
If the VdatDet bit is 0 then the host is a Standard Downstream Port (SDP) and the device will draw the standard
500mA of current and enter the Device USB Operation mode.
If the VdatDet bit is 1 then the host is a charger that can supply at least 1.5A of current, the device will go to the
next mode.
4.
Device enters Device Enhanced Charger Detection mode.
If the VdatDet bit is 0 then the device is connected to a Charging Downstream Port (CDP) and the device will
enter the Device USB Operation mode.
If the VdatDet bit is 1 then the device is connected to a Dedicated Charging Port (DCP) and the device will not
try to enumerate.
5.
The charger detection is complete.
5.9.2
Note:
RESISTIVE CHARGER DETECTION
The Resistive Charger Detection has been superseded by the Active Analog Charger Detection (USB-IF
Battery Charging 1.2) detailed above. It is recommended that new designs use the Active Analog Charger
Detection (USB-IF Battery Charging 1.2).
To support the detection and identification of different types of USB chargers the USB334x provides integrated pull-up
resistors, RCD, on both DP and DM. These pull-up resistors along with the single ended receivers can be used to determine the type of USB charger attached. Reference information on implementing charger detection is provided in
Section 8.2.
TABLE 5-8:
Note:
5.10
Note:
USB WEAK PULL-UP ENABLE
RESETB
DP Pullup Enable
DM Pullup Enable
0
0
0
1
ChargerPullupEnableDP
ChargerPullupEnableDM
ChargerPullupEnableDP and ChargerPullupEnableDM are enabled in the USB IO & Power Management
register.
USB Audio Support (USB3341 and USB3346)
The USB334x supports “USB Digital Audio” through the USB protocol in ULPI and USB Serial modes
described in Section 6.0, "ULPI Operation," on page 42.
The USB334x provides two low resistance analog switches that allow analog audio to be multiplexed over the DP and
DM terminals of the USB connector. The audio switches are shown in . The electrical characteristics of the USB Audio
Switches are provided in Table 4-11.
During normal USB operation the switches are off. When USB Audio is desired the switches can be turned “on” by
enabling the SpkLeftEn, SpkRightEn, or MicEn bits in the Carkit Control register as described in Section 6.7.2, "USB
Audio Mode (USB3341 and USB3346)," on page 61. These bits are disabled by default.
The RESETB pin must be high when using the analog switches so that the VDD33 supply is present. If the VDD33 supply is applied externally and RESETB is held low the switches will be off.
In addition to USB Audio support the switches could also be used to multiplex a second Full Speed USB transceiver to
the USB connector. The signal quality will be degraded slightly due to the “on” resistance of the switches. The USB334x
single-ended receivers described in Section 5.2.1, "USB Transceiver," on page 25 are enabled while in synchronous
mode and are disabled when Carkit Mode is entered.
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USB334x
The USB334x does not provide the DC bias for the audio signals. The SPK_R and SPK_L pins should be biased to
1.65V when audio signals are routed through the USB334x. This DC bias is necessary to prevent the audio signal from
swinging below ground and being clipped by ESD Diodes.
When the system is not using the USB Audio switches, the SPK_R and SPK_L switches should be disabled.
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6.0
ULPI OPERATION
6.1
ULPI Introduction
The USB334x uses the industry standard ULPI digital interface for communication between the transceiver and Link
(device controller). The ULPI interface is designed to reduce the number of pins required to connect a discrete USB
transceiver to an ASIC or digital controller. For example, a full UTMI+ Level 3 OTG interface requires 54 signals while
a ULPI interface requires only 12 signals.
The ULPI interface is documented completely in the “UTMI+ Low Pin Interface (ULPI) Specification Revision 1.1”. The
following sections describe the operating modes of the USB334x digital interface.
Figure 6-1 illustrates the block diagram of the ULPI digital functions. It should be noted that this USB334x does not use
a “ULPI wrapper” around a UTMI+ PHY core as the ULPI specification implies.
FIGURE 6-1:
ULPI DIGITAL BLOCK DIAGRAM
USB Transmit and Receive Logic
Tx Data
Data[7:0]
To TX
Analog
FS/LS Tx Data
High Speed Data
Recovery
Full / Low Speed
Data Recovery
NOTE:
The ULPI interface
is a wrapperless
design.
HS RX Data
To
OTG
Analog
To USB
Audio
Analog
Interface Protect Disable
UseExternal Vbus Indicator
Indicator Complement
Indicator Pass Thru
DischrgVbus
ChrgVbus
IdGndDrv
IdPullUp
SpkLeftEn
SpkRightEn/MicEn
ChargerPullupEnDP
ChargerPullupEnDM
RidValue[2:0]
RidCon...Start
RidCon...Done
Rid State
Machine
VbusValid
SessionValid
SessionEnd
IdGnd
IdFloat
ULPI Interupt
XcvrSelect[1:0]
TermSelect
OpMode[1:0]
Reset
DpPulldown
DmPulldown
SwapDP/DM
RegOutput[1:0]
TxdEn
RxdEn
To RX
Analog
FS/LS Data
Transceiver Control
Rx Data
ULPI Register Access
STP
HS Tx Data
ULPI Protocol
Block
Linestates[1:0]
HostDisconnect
NXT
SuspendM
6pinSerial Mode
3pinSerial Mode
ClockSuspendM
AutoResume
CarkitMode
DIR
High Speed TX
Full Speed TX
Low Speed TX
Interrupt Control
RESETB
POR
ULPI Register Array
The advantage of a “wrapper-less” architecture is that the USB334x has a lower USB latency than a design which must
first register signals into the PHY’s wrapper before the transfer to the transceiver core. A low latency PHY allows a wrapper around a UTMI Link to be used and still make the required USB turn-around timing required by the USB 2.0 specification.
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USB334x
RxEndDelay maximum allowed by the UTMI+/ULPI for 8-bit data is 63 Hi-Speed clocks. USB334x uses a low latency
Hi-Speed receiver path to lower the RxEndDelay to 43 Hi-Speed clocks. This low latency design gives the Link more
cycles to make decisions and reduces the Link complexity. This is the result of the “wrapper less” architecture of the
USB334x. This low RxEndDelay should allow legacy UTMI Links to use a “wrapper” to convert the UTMI+ interface to
a ULPI interface.
In Figure 6-1, a single ULPI Protocol Block decodes the ULPI 8-bit bi-directional bus when the Link addresses the PHY.
The Link must use the DIR output to determine direction of the ULPI data bus. The USB334x is the “bus arbitrator”. The
ULPI Protocol Block will route data/commands to the transmitter or the ULPI register array.
6.1.1
ULPI INTERFACE SIGNALS
The UTMI+ Low Pin Interface (ULPI) uses a 12-pin interface to connect a USB Transceiver to an external Link. The
reduction of external pins, relative to UTMI+, is accomplished implementing the relatively static configuration pins (i.e.
xcvrselect[1:0], termselect, opmode[1:0], and DpPullDown DmPulldown) as an internal register array.
An 8-bit bi-directional data bus clocked at 60 MHz allows the Link to access this internal register array and transfer USB
packets to and from the PHY. The remaining 3 pins function to control the data flow and arbitrate the data bus.
Direction of the 8-bit data bus is controlled by the DIR output from the PHY. Another output, NXT, is used to control
data flow into and out of the device. Finally, STP, which is in input to the PHY, terminates transfers and is used to start
up and resume from Low Power Mode.
The ULPI Interface signals are described below in Table 6-1.
TABLE 6-1:
Signal
ULPI INTERFACE SIGNALS
Direction
Description
CLK
I/O
60 MHz ULPI clock. All ULPI signals are driven synchronous to the rising edge of
this clock. This clock can be either driven by the PHY or the Link as described in
Section 5.5.1, "REFCLK Frequency Selection," on page 28.
DATA[7:0]
I/O
8-bit bi-directional data bus. Bus ownership is determined by DIR. The Link and
PHY initiate data transfers by driving a non-zero pattern onto the data bus. ULPI
defines interface timing for a single-edge data transfers with respect to rising edge
of the ULPI clock.
DIR
OUT
Controls the direction of the data bus. When the PHY has data to transfer to the
Link, it drives DIR high to take ownership of the bus. When the PHY has no data
to transfer it drives DIR low and monitors the bus for commands from the Link. The
PHY will pull DIR high whenever the interface cannot accept data from the Link,
such as during PLL start-up.
STP
IN
The Link asserts STP for one clock cycle to stop the data stream currently on the
bus. If the Link is sending data to the PHY, STP indicates the last byte of data was
on the bus in the previous cycle.
NXT
OUT
The PHY asserts NXT to throttle the data. When the Link is sending data to the
PHY, NXT indicates when the current byte has been accepted by the PHY. The
Link places the next byte on the data bus in the following clock cycle.
USB334x implements a Single Data Rate (SDR) ULPI interface with all data transfers happening on the rising edge of
the 60 MHz ULPI Clock while operating in Synchronous Mode. The direction of the data bus is determined by the state
of DIR. When DIR is high, the PHY is driving DATA[7:0]. When DIR is low, the Link is driving DATA[7:0].
Each time DIR changes, a “turn-around” cycle occurs where neither the Link nor PHY drive the data bus for one clock
cycle. During the “turn-around” cycle, the state of DATA[7:0] is unknown and the PHY will not read the data bus.
Because USB uses a bit-stuffing encoding, some means of allowing the PHY to throttle the USB transmit data is needed.
The ULPI signal NXT is used to request the next byte to be placed on the data bus by the Link.
The ULPI interface supports the two basic modes of operation: Synchronous Mode and Asynchronous Mode. Asynchronous Mode includes Low Power Mode, the Serial Modes, and Carkit Mode. In Synchronous Mode, all signals change
synchronously with the 60 MHz ULPI clock. In asynchronous modes the clock is off and the ULPI bus is redefined to
bring out the signals required for that particular mode of operations. The description of synchronous Mode is described
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USB334x
in the following sections while the descriptions of the asynchronous modes are described in Section 6.5, "Low Power
Mode," on page 55, Section 6.6, "Full Speed/Low Speed Serial Modes," on page 58, and Section 6.7, "Carkit Mode," on
page 59.
6.1.2
ULPI INTERFACE TIMING IN SYNCHRONOUS MODE
The control and data timing relationships are given in Figure 6-2 and Table 4-4. All timing is relative to the rising clock
edge of the 60 MHz ULPI Clock.
FIGURE 6-2:
ULPI SINGLE DATA RATE TIMING DIAGRAM IN SYNCHRONOUS MODE
60MHz ULPI CLK
TSC
THC
Control In STP
TSD
THD
Data In DATA[7:0]
TDC
TDC
Control Out DIR, NXT
TDD
Data Out DATA[7:0]
6.2
ULPI Register Access
The following section details the steps required to access registers through the ULPI interface. At any time DIR is low
the Link may access the ULPI registers set using the Transmit Command byte. The ULPI registers retain their contents
when the PHY is in Low Power Mode, Full Speed/Low Speed Serial Mode, or Carkit Mode.
6.2.1
TRANSMIT COMMAND BYTE (TX CMD)
A command from the Link begins a ULPI transfer from the Link to the USB334x. Before reading a ULPI register, the Link
must wait until DIR is low, and then send a Transmit Command Byte (TX CMD) byte. The TX CMD byte informs the
USB334x of the type of data being sent. The TX CMD is followed by a data transfer to or from the USB334x. Table 6-2
gives the TX command byte (TX CMD) encoding for the USB334x. The upper two bits of the TX CMD instruct the PHY
as to what type of packet the Link is transmitting.
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USB334x
TABLE 6-2:
ULPI TX CMD BYTE ENCODING
Command Name
CMD Bits[7:6]
CMD Bits[5:0]
Idle
00b
000000b
ULPI Idle
Transmit
01b
000000b
USB Transmit Packet with No Packet Identifier
(NOPID)
00XXXXb
USB Transmit Packet Identifier (PID) where DATA[3:0]
is equal to the 4-bit PID. P3P2P1P0 where P3 is the
MSB.
XXXXXXb
Immediate Register Write Command where:
DATA[5:0] = 6-bit register address
Register Write
10b
101111b
Register Read
11b
Extended Register Write Command where the 8-bit
register address is available on the next cycle.
XXXXXXb
Immediate Register Read Command where:
DATA[5:0] = 6-bit register address
101111b
6.2.2
Command Description
Extended Register Read Command where the 8-bit
register address is available on the next cycle.
ULPI REGISTER WRITE
A ULPI register write operation is given in Figure 6-3. The TX command with a register write DATA[7:6] = 10b is driven
by the Link at T0. The register address is encoded into DATA[5:0] of the TX CMD byte.
FIGURE 6-3:
ULPI REGISTER WRITE IN SYNCHRONOUS MODE
T0
T1
T2
T3
T4
T5
T6
CLK
DATA[7:0]
Idle
TXD CMD
(reg write)
Reg Data[n]
Idle
DIR
STP
NXT
ULPI Register
Reg Data [n-1]
Reg Data [n]
To write a register, the Link will wait until DIR is low, and at T0, drive the TX CMD on the data bus. At T2 the PHY will
drive NXT high. On the next rising clock edge, T3, the Link will write the register data. At T4, the PHY will accept the
register data and drive NXT low. The Link will drive an Idle on the bus and drive STP high to signal the end of the data
packet. Finally, at T5, the PHY will latch the data into the register and the Link will pull STP low.
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NXT is used to throttle when the Link drives the register data on the bus. DIR is low throughout this transaction since
the PHY is receiving data from the Link. STP is used to end the transaction and data is registered after the de-assertion
of STP. After the write operation completes, the Link must drive a ULPI Idle (00h) on the data bus. If the databus is not
driven to idle the USB334x may decode the non-zero bus value as an RX Command.
A ULPI extended register write operation is shown in Figure 6-4. To write an extended register, the Link will wait until
DIR is low, and at T0, drive the TX CMD on the data bus. At T2 the PHY will drive NXT high. On the next clock T3 the
Link will drive the extended address. On the next rising clock edge, T4, the Link will write the register data. At T5, the
PHY will accept the register data and drive NXT low. The Link will drive an Idle on the bus and drive STP high to signal
the end of the data packet. At T5, the PHY will latch the data into the register. Finally, at T6, the Link will drive STP low.
FIGURE 6-4:
ULPI EXTENDED REGISTER WRITE IN SYNCHRONOUS MODE
T0
T1
T2
T3
T4
T5
T6
T7
CLK
DATA[7:0]
Idle
TXD CMD
(extended reg write)
Extended
address
Reg Data[n]
Idle
DIR
STP
NXT
ULPI Register
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Reg Data [n-1]
Reg Data [n]
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USB334x
6.2.3
ULPI REGISTER READ
A ULPI register read operation is given in Figure 6-5. The Link drives a TX CMD byte with DATA[7:6] = 11h for a register
read. DATA[5:0] of the ULPI TX command bye contain the register address.
FIGURE 6-5:
ULPI REGISTER READ IN SYNCHRONOUS MODE
T0
T1
T2
T3
T4
T5
T6
CLK
DATA[7:0]
Idle
TXD CMD
reg read
Turn around
Reg Data
Turn around
Idle
DIR
STP
NXT
At T0, the Link will place the TX CMD on the data bus. At T2, the PHY will bring NXT high, signaling the Link it is ready
to accept the data transfer. At T3, the PHY reads the TX CMD, determines it is a register read, and asserts DIR to gain
control of the bus. The PHY will also de-assert NXT. At T4, the bus ownership has transferred back to the PHY and the
PHY drives the requested register onto the data bus. At T5, the Link will read the data bus and the PHY will drop DIR
low returning control of the bus back to the Link. After the turn around cycle, the Link must drive a ULPI Idle command
at T6.
A ULPI extended register read operation is shown in Figure 6-6.To read an extended register, the Link writes the TX
CMD with the address set to 2Fh. At T2, the PHY will assert NXT, signaling the Link it is ready to accept the extended
address. At T3, the Link places the extended register address on the bus. At T4, the PHY reads the extended address,
and asserts DIR to gain control of the bus. The PHY will also de-assert NXT. At T5, the bus ownership has transferred
back to the PHY and the PHY drives the requested register onto the data bus. At T6, the Link will read the data bus and
the PHY will de-assert DIR returning control of the bus back to the Link. After the turn around cycle, the Link must drive
a ULPI Idle command at T6.
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USB334x
FIGURE 6-6:
ULPI EXTENDED REGISTER READ IN SYNCHRONOUS MODE
T0
T1
T2
T3
T4
T5
T6
T7
CLK
DATA[7:0]
Idle
TXD CMD
extended reg read
Extended
address
Turn around
Reg Data
Turn around
Idle
DIR
STP
NXT
6.3
USB334x Receiver
The following section describes how the USB334x uses the ULPI interface to receive USB signaling and transfer status
information to the Link. This information is communicated to the Link using RX Commands to relay bus status and
received USB packets.
6.3.1
ULPI RECEIVE COMMAND (RX CMD)
The ULPI Link needs information which was provided by the following pins in a UTMI implementation: linestate[1:0],
rxactive, rxvalid, rxerror, and VbusValid. When implementing the OTG functions, the VBUS and ID pin states must also
be transferred to the Link. ULPI defines a Receive Command Byte (RXCMD) that contains this information.
An RXCMD can be sent a any time the bus is idle. The RXCMD is initiated when the USB334x asserts DIR to take control of the bus. The timing of RXCMD is shown in the figure below. The USB334x can send single or back to back
RXCMD’s as required. The Encoding of the RXCMD byte is given in the Table 6-3.
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USB334x
FIGURE 6-7:
ULPI RXCMD TIMING
T0
T1
T2
T3
T4
T5
T6
T7
T8
CLK
DATA[7:0]
Idle
Turn around
RXCMD
Turn around
Idle
Turn around
RXCMD
RXCMD
Turn around
Idle
DIR
STP
NXT
Transfer of the RXCMD byte occurs in Synchronous Mode when the PHY has control of the bus. The ULPI Protocol
Block shown in Figure 6-1 determines when to send an RXCMD. A RXCMD will occur:
•
•
•
•
•
When a linestate change occurs.
When VBUS or ID comparators change state.
During a USB receive when NXT is low.
After the USB334x deasserts DIR and STP is low during start-up
After the USB334x exits Low Power Mode, Serial Modes, or Carkit Mode after detecting that the Link has deasserted STP, and DIR is low.
When a USB Receive is occurring, RXCMD’s are sent whenever NXT = 0 and DIR = 1. During a USB Transmit, the
RXCMD’s are returned to the Link after STP is asserted.
If an RXCMD event occurs during a Hi-Speed USB transmit, the RXCMD is blocked until STP de-asserts at the end of
the transmit. The RXCMD contains the status that is current at the time the RXCMD is sent.
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USB334x
TABLE 6-3:
ULPI RX CMD ENCODING
Data [7:0]
Name
[1:0]
Linestate
UTMI Linestate Signals. See Section 6.3.1.1, "Definition of Linestate," on page 50
[3:2]
Encoded
VBUS
State
ENCODED VBUS VOLTAGE STATES
[5:4]
Rx Event
Encoding
[6]
State of
ID pin
[7]
alt_int
Description and Value
VALUE
VBUS VOLTAGE
SESSEND
SESSVLD
VBUSVLD2
00
VVBUS < VSESS_END
1
0
0
01
VSESS_END < VVBUS <
VSESS_VLD
0
0
0
10
VSESS_VLD < VVBUS <
VVBUS_VLD
X
1
0
11
VVBUS_VLD < VVBUS
X
X
1
ENCODED UTMI EVENT SIGNALS
VALUE
RXACTIVE
RXERROR
HOSTDISCONNECT
00
0
0
0
01
1
0
0
11
1
1
0
10
X
X
1
Set to the logic state of the ID pin. A logic low indicates an A device. A logic high
indicates a B device.
Asserted when a non-USB interrupt occurs. This bit is set when an unmasked event
occurs on any bit in the Carkit Interrupt Latch register. The Link must read the Carkit
Interrupt Latch register to determine the source of the interrupt. Section 6.8, "RID
Converter Operation," on page 61 describes how an interrupt can be generated when
the RidConversionDone bit is set.
Note 1: An ‘X’ is a do not care and can be either a logic 0 or 1.
2: The value of VbusValid is defined in Table 5-5.
6.3.1.1
Definition of Linestate
The Linestate information is used to relay information back to the Link on the current status of the USB data lines, DP
and DM. The definition of Linestate changes as the USB334x transitions between LS/FS mode, HS mode, and HS
Chirp.
6.3.1.1.1
LS/FS Linestate Definitions
In LS and FS operating modes the Linestate is defined by the outputs of the LS/FS Single Ended Receivers (SE RX).
The logic thresholds for single ended receivers, VILSE and VILSE are shown in Table 4-6.
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USB334x
TABLE 6-4:
USB LINESTATE DECODING IN FS AND LS MODE
Linestate[1:0]
DP SE RX
DM SE RX
State
00
SE0
0
0
USB Reset
01
J (FS idle)
1
0
J State
10
K (LS Idle)
0
1
K State
11
SE1
1
1
SE1
Low Speed uses the same Linestate decoding threshold as Full Speed. Low Speed re-defines the Idle state as an inversion of the Full Speed idle to account for the inversion which occurs in the hub repeater path. Linestates are decoded
exactly as in Table 6-4 with the idle as a K state.
6.3.1.1.2
HS Linestate Definition
In HS mode the data transmission is too fast for Linestate to be transmitted with each transition in the data packet. In
HS operation the Linestate is redefined to indicate activity on the USB interface. The Linestate will signal the assertion
and de-assertion of squelch in HS mode.
TABLE 6-5:
USB LINESTATE DECODING IN HS MODE
Linestate[1:0]
DP SE RX
DM SE RX
State
00
SE0
0
0
HS Squelch asserted
01
J
1
0
HS Squelch de-asserted
10
K
0
1
Invalid State
11
SE1
1
1
Invalid State
6.3.1.1.3
HS CHIRP Linestate Definition
There is also a third use of Linestate in HS Chirp where when the Host and Peripheral negotiate the from FS mode to
HS mode. While the transitions from K to J or SE0 are communicated to the Link through the Linestate information.
TABLE 6-6:
USB LINESTATE DECODING IN HS CHIRP MODE
Linestate[1:0]
DP SE RX
DM SE RX
State
00
SE0
0
0
HS Squelch asserted
01
J
1
0
HS Squelch de-asserted & HS
differential Receiver = 1
10
K
0
1
HS Squelch de-asserted & HS
differential Receiver = 0
11
SE1
1
1
Invalid State
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USB334x
6.3.2
USB RECEIVER
The USB334x ULPI receiver fully supports HS, FS, and LS transmit operations. In all three modes the receiver detects
the start of packet and synchronizes to the incoming data packet. In the ULPI protocol, a received packet has the priority
and will immediately follow register reads and RXCMD transfers. Figure 6-8 shows a basic USB packet received by the
USB334x over the ULPI interface.
FIGURE 6-8:
ULPI RECEIVE IN SYNCHRONOUS MODE
CLK
DATA[7:0]
Idle
Turn
around
Rxd
Cmd
PID
D1
Rxd
Cmd
D2
Turn
around
DIR
STP
NXT
In Figure 6-8 the PHY asserts DIR to take control of the data bus from the Link. The assertion of DIR and NXT in the
same cycle contains additional information that Rxactive has been asserted. When NXT is de-asserted and DIR is
asserted, the RXCMD data is transferred to the Link. After the last byte of the USB receive packet is transferred to the
PHY, the linestate will return to idle.
The ULPI Full Speed receiver operates according to the UTMI / ULPI specification. In the Full Speed case, the NXT
signal will assert only when the Data bus has a valid received data byte. When NXT is low with DIR high, the RXCMD
is driven on the data bus.
In Full Speed, the USB334x will not issue a Rxactive de-assertion in the RXCMD until the DP/DM linestate transitions
to idle. This prevents the Link from violating the two Full Speed bit times minimum turn around time.
6.3.2.1
Disconnect Detection
A Hi-Speed host must detect a disconnect by sampling the transmitter outputs during the long EOP transmitted during
a SOF packet. The USB334x only looks for a Hi-Speed disconnect during the long EOP where the period is long enough
for the disconnect reflection to return to the host PHY. When a Hi-Speed disconnect occurs, the USB334x will return a
RXCMD and set the host disconnect bit in the USB Interrupt Status register.
When in FS or LS modes, the Link is expected to handle all disconnect detection.
6.3.2.2
Link Power Management (LPM) Token Receive
The USB334x is fully capable of receiving the Extended PID in the LPM token. When the LPM 0000b PID is received,
this information is passed to the Link as a normal receive packet. If the Link chooses to enter LPM suspend, the procedure detailed in Section 6.5.3, "Link Power Management (LPM)," on page 57 can be followed.
6.4
USB334x Transmitter
The USB334x ULPI transmitter fully supports HS, FS, and LS transmit operations. Figure 6-1 shows the Hi-Speed, Full
Speed, and Low Speed transmitter block controlled by ULPI Protocol Block. Encoding of the USB packet follows the bitstuffing and NRZI outlined in the USB 2.0 specification. Many of these functions are reused between the HS and FS/LS
transmitters. When using the USB334x, Table 5-1 should always be used as a guideline on how to configure for various
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USB334x
modes of operation. The transmitter decodes the inputs of XcvrSelect[1:0], TermSelect, OpMode[1:0], DpPulldown, and
DmPulldown to determine what operation is expected. Users must strictly adhere to the modes of operation given in
Table 5-1.
Several important functions for a device and host are designed into the transmitter blocks.
The USB334x transmitter will transmit a 32-bit long Hi-Speed sync before every Hi-Speed packet. In Full and Low Speed
modes a 8-bit sync is transmitted.
When the device or host needs to chirp for Hi-Speed port negotiation, the OpMode = 10 setting will turn off the bit-stuffing
and NRZI encoding in the transmitter. At the end of a chirp, the USB334x OpMode register bits should be changed only
after the RXCMD linestate encoding indicates that the transmitter has completed transmitting. Should the opmode be
switched to normal bit-stuffing and NRZI encoding before the transmit pipeline is empty, the remaining data in the pipeline may be transmitted in an bit-stuff encoding format.
Please refer to the ULPI specification for a detailed discussion of USB reset and HS chirp.
6.4.1
USB334X HOST FEATURES
The USB334x can also support USB Host operation and includes the following features that are required for Host operation.
6.4.1.1
Hi-Speed Long EOP
When operating as a Hi-Speed host, the USB334x will automatically generate a 40 bit long End of Packet (EOP) after
a SOF PID (A5h). The USB334x determines when to send the 40-bit long EOP by decoding the ULPI TX CMD bits [3:0]
for the SOF. The 40-bit long EOP is only transmitted when the DpPulldown and DmPulldown bits in the OTG Control
register are asserted. The Hi-Speed 40-bit long EOP is used to detect a disconnect in mode.
In device mode, the USB334x will not send a long EOP after a SOF PID.
6.4.1.2
Low Speed Keep-Alive
Low Speed keep alive is supported by the USB334x. When in Low Speed mode, the USB334x will send out two Low
Speed bit times of SE0 when a SOF PID is received.
6.4.1.3
UTMI+ Level 3
Pre-amble is supported for UTMI+ Level 3 compatibility. When XcvrSelect is set to (11b) in host mode, (DpPulldown and
DmPulldown both asserted) the USB334x will pre-pend a Full Speed pre-amble before the Low Speed packet. Full
Speed rise and fall times are used in this mode. The pre-amble consists of the following: Full Speed sync, the encoded
pre-PID (C3h) and then Full Speed idle (DP=1 and DM = 0). A Low Speed packet follows with a sync, data and a LS EOP.
The USB334x will only support UTMI+ Level 3 as a host. The USB334x does not support UTMI+ Level 3 as a peripheral.
A UTMI+ Level 3 peripheral is an upstream hub port. The USB334x will not decode a pre-amble packet intended for a
LS device when the USB334x is configured as the upstream port of a FS hub, XcvrSelect = 11b, DpPulldown = 0b,
DmPulldown =0b.
6.4.1.4
Host Resume K
Resume K generation is supported by the USB334x. At the end of a USB Suspend the PHY will drive a K back to the
downstream device. When the USB334x exits from Low Power Mode, when operating as a host, it will automatically
transmit a Resume K on DP/DM. The transmitters will end the K with SE0 for two Low Speed bit times. If the USB334x
was operating in Hi-Speed mode before the suspend, the host must change to Hi-Speed mode before the SE0 ends.
SE0 is two Low Speed bit times which is about 1.2 us. For more details please see sections 7.1.77 and 7.9 of the USB
Specification.
In device mode, the resume K will not append an SE0, but release the bus to the correct idle state, depending upon the
operational mode as shown in Table 5-1.
The ULPI specification includes a detailed discussion of the resume sequence and the order of operations required. To
support Host start-up of less than 1mS the USB334x implements the ULPI AutoResume bit in the Interface Control register. The default AutoResume state is 0 and this bit should be enabled for Host applications.
6.4.1.5
No SYNC and EOP Generation (OpMode = 11)
UTMI+ defines OpMode = 11 where no sync and EOP generation occurs in Hi-Speed operation. This is an option to the
ULPI specification and not implemented in the USB334x.
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USB334x
6.4.2
TYPICAL USB TRANSMIT WITH ULPI
Figure 6-9 shows a typical USB transmit sequence. A transmit sequence starts by the Link sending a TX CMD where
DATA[7:6] = 01b, DATA[5:4] = 00b, and Data[3:0] = PID. The TX CMD with the PID is followed by transmit data.
FIGURE 6-9:
ULPI TRANSMIT IN SYNCHRONOUS MODE
CLK
DATA[7:0]
TXD CMD
(USB tx)
Idle
D0
D1
D2
D3
IDLE
Turn
Around
RXD
CMD
Turn
Around
DIR
NXT
STP
DP/DM
SE0
!SQUELCH
SE0
During transmit the PHY will use NXT to control the rate of data flow into the PHY. If the USB334x pipeline is full or bitstuffing causes the data pipeline to overfill NXT is de-asserted and the Link will hold the value on Data until NXT is
asserted. The USB Transmit ends when the Link asserts STP while NXT is asserted.
Note:
The Link cannot assert STP with NXT de-asserted since the USB334x is expecting to fetch another byte
from the Link.
After the USB334x completes transmitting, the DP and DM lines return to idle and a RXCMD is returned to the Link so
the inter-packet timers may be updated by linestate.
While operating in Full Speed or Low Speed, an End-of-Packet (EOP) is defined as SE0 for approximately two bit times,
followed by J for one bit time. The transceiver drives a J state for one bit time following the SE0 to complete the EOP.
The Link must wait for one bit time following line state indication of the SE0 to J transition to allow the transceiver to
complete the one bit time J state. All bit times are relative to the speed of transmission.
In the case of Full Speed or Low Speed, after STP is asserted each FS/LS bit transition will generate a RXCMD since
the bit times are relatively slow.
6.4.2.1
Link Power Management Token Transmit
A Host Link can send a LPM command using the USB334x. When sending the LPM token the normal transmit method
is not used. Sending a LPM token requires the USB334x to send a 0000b or ‘F0’ PID. When the ULPI specification was
defined the ‘F0’ PID was not defined. The ULPI specification used the “Reserved” ‘F0’ PID to signal chirp and resume
signaling while using OpMode 10b. While in OpMode 00b the USB334x is able to generate the ‘F0’ PID as shown below.
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USB334x
FIGURE 6-10:
LPM TOKEN TRANSMIT
CLK
DATA[7:0]
Idle
TXD CMD
(40h TX NOPID )
PID
(F0h)
D0
D1
Turn
Around
IDLE
Turn
Around
RXD
CMD
IDLE
DIR
NXT
STP
DP/DM
SE0
!SQUELCH
SE0
To send the ‘F0’ PID, the link will be required to use the TX CMD with NOPID to initiate the transmit and then follow up
the TX CMD with the ‘F0’ PID. The data bytes follow as in a normal transmit, in OpMode 00b. The key difference is in
that the link will have to send the PID the same as it would send a data packet. The USB334x is able to recognize the
LPM transmit and correctly send the PID information.
6.5
Low Power Mode
Low Power Mode is a power down state to save current when the USB session is suspended. The Link controls when
the PHY is placed into or out of Low Power Mode. In Low Power Mode all of the circuits are powered down except the
interface pins, Full Speed receiver, VBUS comparators, and IdGnd comparator. The VBUS and ID comparators can
optionally be powered down to save current as shown in Section 6.5.5, "Minimizing Current in Low Power Mode," on
page 58.
Before entering Low Power Mode, the USB334x must be configured to set the desired state of the USB transceiver. The
XcvrSelect[1:0], TermSelect and OpMode[1:0] bits in the Function Control register, and the DpPulldown and DmPulldown bits in the OTG Control register control the configuration as shown in Table 5-1. The DP and DM pins are configured to a high impedance state by configuring OpMode[1:0] = 01 as shown in the programming example in Table 6-8.
Pull-down resistors with a value of approximately 2MΩ are present on the DP and DM pins to avoid false linestate indications that could result if the pins were allowed to float.
6.5.1
ENTERING LOW POWER/SUSPEND MODE
To enter Low Power Mode, the Link will write a 0 or clear the SuspendM bit in the Function Control register. After this
write is complete, the PHY will assert DIR high and after a minimum of five rising edges of CLKOUT, drive the clock low.
After the clock is stopped, the PHY will enter a low power state to conserve current. Placing the PHY in Suspend Mode
is not related to USB Suspend. To clarify this point, USB Suspend is initiated when a USB host stops data transmissions
and enters Full-Speed mode with 15KΩ pull-down resistors on DP and DM. The suspended device goes to Full-Speed
mode with a pull-up on DP. Both the host and device remain in this state until one of them drives DM high (this is called
a resume).
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USB334x
FIGURE 6-11:
ENTERING LOW POWER MODE FROM SYNCHRONOUS MODE
T0
T1
T2
T3
T4
T5
T6
CLK
DATA[7:0]
Idle
TXD CMD
(reg write)
Reg Data[n]
Idle
Turn
Around
...
T10
Low Power Mode
DIR
STP
NXT
SUSPENDM
(ULPI Register Bit)
While in Low Power Mode, the Data interface is redefined so that the Link can monitor Linestate and the VBUS voltage.
In Low Power Mode DATA[3:0] are redefined as shown in Table 6-7. Linestate[1:0] is the combinational output of the
Single-Ended Receivers. The “int” or interrupt signal indicates an unmasked interrupt has occurred. When an unmasked
interrupt or linestate change has occurred, the Link is notified and can determine if it should wake-up the PHY.
TABLE 6-7:
Signal
INTERFACE SIGNAL MAPPING DURING LOW POWER MODE
Maps to
Direction
Description
linestate[0]
DATA[0]
OUT
Combinatorial LineState[0] driven directly by the Full-Speed single
ended receiver. Note 6-1
linestate[1]
DATA[1]
OUT
Combinatorial LineState[1] driven directly by the Full-Speed single
ended receiver. Note 6-1
reserved
DATA[2]
OUT
Driven Low
int
DATA[3]
OUT
Active high interrupt indication. Must be asserted whenever any
unmasked interrupt occurs.
reserved
DATA[7:4]
OUT
Driven Low
Note 6-1
LineState: These signals reflect the current state of the Full-Speed single ended receivers.
LineState[0] directly reflects the current state of DP. LineState[1] directly reflects the current state of
DM. When DP=DM=0 this is called "Single Ended Zero" (SE0). When DP=DM=1, this is called
"Single Ended One" (SE1).
An unmasked interrupt can be caused by the following comparators changing state: VbusVld, SessVld, SessEnd, and
IdGnd. If any of these signals change state during Low Power Mode and the bits are enabled in either the USB Interrupt
Enable Rising or USB Interrupt Enable Falling registers, DATA[3] will assert. During Low Power Mode, the VbusVld and
SessEnd comparators can have their interrupts masked to lower the suspend current as described in Section 6.5.5,
"Minimizing Current in Low Power Mode," on page 58.
While in Low Power Mode, the Data bus is driven asynchronously because all of the PHY clocks are stopped during
Low Power Mode.
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USB334x
6.5.2
EXITING LOW POWER MODE
To exit Low Power Mode, the Link will assert STP. Upon the assertion of STP, the USB334x will begin its start-up procedure. After the PHY start-up is complete, the PHY will start the clock on CLKOUT and de-assert DIR. After DIR has
been de-asserted, the Link can de-assert STP when ready and start operating in Synchronous Mode. The PHY will automatically set the SuspendM bit to a 1 in the Function Control register.
FIGURE 6-12:
EXITING LOW POWER MODE
T0
...
CLK
DATA[7:0]
LOW
POWER MODE
T1
T2
TURN
AROUND
T3
DATA BUS IGNORED (SLOW LINK)
IDLE (FAST LINK)
Fast Link Drives Bus
Idle and STP low
DIR
T4
T5
IDLE
Slow Link Drives Bus
Idle and STP low
STP
Note: Not to Scale
TSTART
The value for TSTART is given in Table 4-3.
Should the Link de-assert STP before DIR is de-asserted, the USB334x will detect this as a false resume request and
return to Low Power Mode. This is detailed in Section 3.9.4 of the UTMI+ Low Pin Interface (ULPI) Specification Revision
1.1.
6.5.3
LINK POWER MANAGEMENT (LPM)
When the USB334x is operating with a Link capable of Link Power Management, the Link will place the USB334x in and
out of suspend rapidly to conserve power. The USB334x provides a fast suspend recovery that allows the USB334x to
meet the suspend recovery time detailed in the Link Power Management ECN to the USB 2.0 specification.
When the Link places the USB334x into suspend during Link Power Management, the LPM Enable bit of the HS Compensation Register must be set to 1. This allows the USB334x to start-up in the time specified in Table 4-3.
6.5.4
INTERFACE PROTECTION
ULPI protocol assumes that both the Link and PHY will keep the ULPI data bus driven by either the Link when DIR is
low or the PHY when DIR is high. The only exception is when DIR has changed state and a turn around cycle occurs
for 1 clock period.
In the design of a USB system, there can be cases where the Link may not be driving the ULPI bus to a known state
while DIR is low. Two examples where this can happen is because of a slow Link start-up or a hardware reset.
6.5.4.1
Start up Protection
Upon start-up, when the PHY de-asserts DIR, the Link must be ready to receive commands and drive Idle on the data
bus. If the Link is not ready to receive commands or drive Idle, it must assert STP before DIR is de-asserted. The Link
can then de-assert STP when it has completed its start-up. If the Link doesn’t assert STP before it can receive commands, the PHY may interpret the data bus state as a TX CMD and transmit invalid data onto the USB bus, or make
invalid register writes.
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USB334x
When the USB334x sends a RXCMD the Link is required to drive the data bus back to idle at the end of the turn around
cycle. If the Link does not drive the databus to idle the USB334x may take the information on the data bus as a TXCMD
and transmit data on DP and DM until the Link asserts stop. If the ID pin is floated the last RXCMD from the USB334x
will remain on the bus after DIR is de-asserted and the USB334x will take this in as a TXCMD.
A Link should be designed to have the default POR state of the STP output high and the data bus tri-stated. The
USB334x has weak pull-downs on the data bus to prevent these inputs from floating when not driven. These resistors
are only used to prevent the ULPI interface from floating during events when the link ULPI pins may be tri-stated. The
strength of the pull down resistors can be found in Table 4-5. The pull downs are not strong enough to pull the data bus
low after a ULPI RXCMD, the Link must drive the data bus to idle after DIR is de-asserted.
In some cases, a Link may be software configured and not have control of its STP pin until after the PHY has started.
In this case, the USB334x has in internal pull-up on the STP input pad which will pull STP high while the Link’s STP
output is tri-stated. The STP pull-up resistor is enabled on POR and can be disabled by setting the InterfaceProtectDisable bit 7 of the Interface Control register.
The STP pull-up resistor will pull-up the Link’s STP input high until the Link configures and drives STP high. After the
Link completes its start-up, STP can be synchronously driven low.
A Link design which drives STP high during POR can disable the pull-up resistor on STP by setting InterfaceProtectDisable bit to 1. A motivation for this is to reduce the suspend current. In Low Power Mode, STP is held low, which would
draw current through the pull-up resistor on STP.
6.5.4.2
Warm Reset
Designers should also consider the case of a warm restart of a Link with a PHY in Low Power Mode. After the PHY
enters Low Power Mode, DIR is asserted and the clock is stopped. The USB334x looks for STP to be asserted to restart the clock and then resume normal synchronous operation.
Should the USB334x be suspended in Low Power Mode, and the Link receives a hardware reset, the PHY must be able
to recover from Low Power Mode and start its clock. If the Link asserts STP on reset, the PHY will exit Low Power Mode
and start its clock.
If the Link does not assert STP on reset, the interface protection pull-up can be used. When the Link is reset, its STP
output will tri-state and the pull-up resistor will pull STP high, signaling the PHY to restart its clock.
6.5.5
MINIMIZING CURRENT IN LOW POWER MODE
In order to minimize the suspend current in Low Power Mode, the VBUS and ID comparators can be disabled to reduce
suspend current. In Low Power Mode, the VbusVld and SessEnd comparators are not needed and can be disabled by
clearing the associated bits in both the USB Interrupt Enable Rising and USB Interrupt Enable Falling registers. By disabling the interrupt in BOTH the rise and fall registers, the SessEnd and VbusVld comparators are turned off. The
IdFloatRise and IdFloatFall bits in Carkit Interrupt Enable register should also be disabled if they were set. When exiting
Low Power Mode, the Link should immediately re-enable the VbusVld and SessEnd comparators if host or OTG functionality is required.
In addition to disabling the OTG comparators in Low Power Mode, the Link may choose to disable the Interface Protect
Circuit. By setting the InterfaceProtectDisable bit high in the Interface Control register, the Link can disable the pull-up
resistor on STP. When RESETB is low the Interface Protect Circuit will be disabled.
6.6
Full Speed/Low Speed Serial Modes
The USB334x includes two serial modes to support legacy Links which use either the 3pin or 6pin serial format. To enter
either serial mode, the Link will need to write a 1 to the 6-pin FsLsSerialMode or the 3-pin FsLsSerialMode bits in the
Interface control register. Serial Mode may be used to conserve power when attached to a device that is not capable of
operating in Hi-Speed.
The serial modes are entered in the same manner as the entry into Low Power Mode. The Link writes the Interface
Control register bit for the specific serial mode. The USB334x will assert DIR and shut off the clock after at least five
clock cycles. Then the data bus goes to the format of the serial mode selected. Before entering Serial Mode the Link
must set the ULPI transceiver to the appropriate mode as defined in Table 5-1.
In ULPI Clock Output Mode, the PHY will shut off the 60 MHz clock to conserve power. Should the Link need the 60 MHz
clock to continue during the serial mode of operation, the ClockSuspendM bit[3] of the Interface Control Register should
be set before entering a serial mode. If set, the 60 MHz clock will be present during serial modes.
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USB334x
In serial mode, interrupts are possible from unmasked sources. The state of each interrupt source is sampled prior to
the assertion of DIR and this is compared against the asynchronous level from interrupt source.
Exiting the serial modes is the same as exiting Low Power Mode. The Link must assert STP to signal the PHY to exit
serial mode. When the PHY can accept a command, DIR is de-asserted and the PHY will wait until the Link de-asserts
STP to resume synchronous ULPI operation. The RESETB pin can also be pulsed low to reset the USB334x and return
it to Synchronous Mode.
6.6.1
3-PIN FS/LS SERIAL MODE
Three pin serial mode utilizes the data bus pins for the serial functions shown in Table 6-8.
TABLE 6-8:
PIN DEFINITIONS IN 3 PIN SERIAL MODE
Signal
Connected to
Direction
tx_enable
DATA[0]
IN
Active High transmit enable.
data
DATA[1]
I/O
TX differential data on DP/DM when tx_enable is high.
RX differential data from DP/DM when tx_enable is low.
SE0
DATA[2]
I/O
TX SE0 on DP/DM when tx_enable is high.
RX SE0_b from DP/DM when tx_enable is low.
interrupt
DATA[3]
OUT
Asserted when any unmasked interrupt occurs. Active high.
Reserved
DATA[7:4]
OUT
Driven Low.
6.6.2
Description
6-PIN FS/LS SERIAL MODE
Six pin serial mode utilizes the data bus pins for the serial functions shown in Table 6-9.
TABLE 6-9:
PIN DEFINITIONS IN 6 PIN SERIAL MODE
Signal
Connected to
Direction
tx_enable
DATA[0]
IN
Active High transmit enable.
tx_data
DATA[1]
IN
Tx differential data on DP/DM when tx_enable is high.
tx_se0
DATA[2]
IN
Tx SE0 on DP/DM when tx_enable is high.
interrupt
DATA[3]
OUT
Asserted when any unmasked interrupt occurs. Active high.
rx_dp
DATA[4]
OUT
Single ended receive data on DP.
rx_dm
DATA[5]
OUT
Single ended receive data on DM.
rx_rcv
DATA[6]
OUT
Differential receive data from DP and DM.
Reserved
DATA[7]
OUT
Driven Low.
6.7
Description
Carkit Mode
The USB334x includes Carkit Mode to support a USB UART and USB Audio Mode.
By entering Carkit Mode, the USB334x current drain is minimized. The internal PLL is disabled and the 60 MHz ULPI
CLKOUT will be stopped to conserve power by default. The Link may configure the 60 MHz clock to continue by setting
the ClockSuspendM bit of the Interface Control register before entering Carkit Mode. If set, the 60 MHz clock will continue during the Carkit Mode of operation.
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USB334x
In Carkit Mode, interrupts are possible if they have been enabled in the Carkit Interrupt Enable register. The state of
each interrupt source is sampled prior to the assertion of DIR and this is compared against the asynchronous level from
interrupt source. In Carkit Mode, the Linestate signals are not available per the ULPI specification.
The ULPI interface is redefined to the following when Carkit Mode is entered.
TABLE 6-10:
PIN DEFINITIONS IN CARKIT MODE
Signal
Connected to
Direction
Description
txd
DATA[0]
IN
UART TXD signal that is routed to the DM pin if the TxdEn
is set in the Carkit Control register.
rxd
DATA[1]
OUT
UART RXD signal that is routed to the DP pin if the RxdEn
bit is set in the Carkit Control register.
reserved
DATA[2]
OUT
Driven Low (CarkitDataMC = 0, default)
IN
Tri-state (CarkitDataMC = 1)
int
DATA[3]
OUT
Asserted when any unmasked interrupt occurs. Active high.
reserved
DATA[4:7]
OUT
Driven Low.
Exiting Carkit Mode is the same as exiting Low Power Mode as described in Section 6.5.2, "Exiting Low Power Mode,"
on page 57. The Link must assert STP to signal the PHY to exit serial mode. When the PHY can accept a command,
DIR is de-asserted and the PHY will wait until the Link de-asserts STP to resume synchronous ULPI operation. The
RESETB pin can also be pulsed low to reset the USB334x and return it to Synchronous Mode.
6.7.1
ENTERING USB UART MODE
The USB334x can be placed into UART Mode by first setting the TxdEn and RxdEn bits in the Carkit Control register.
Then the Link can set the CarkitMode bit in the Interface Control register. The TxdEn and RxdEn bits must be written
before the CarkitMode bit.
TABLE 6-11:
ULPI REGISTER PROGRAMMING EXAMPLE TO ENTER UART MODE
R/W
Address
(HEX)
Value
(HEX)
W
04
W
Description
Result
49
Configure Non-Driving mode
Select FS transmit edge rates
OpMode=01
XcvrSelect=01
39
00
Set regulator to 3.3V
UART RegOutput=00
W
19
0C
Enable UART connections
RxdEn=1
TxdEn=1
W
07
04
Enable carkit mode
CarkitMode=1
After the CarkitMode bit is set, the ULPI interface will become redefined as described in Table 6-10, and the USB334x
will transmit data through the DATA[0] to DM of the USB connector and receive data on DP and pass the information
the Link on DATA[1].
When entering UART mode, the regulator output will automatically switch to the value configured by the UART RegOutput bits in the USB IO & Power Management register and the RCD pull-up resistors will be applied internally to DP and
DM. This will hold the UART in its default operating state.
While in UART mode, the transmit edge rates can be set to either the Full Speed USB or Low Speed USB edge rates
by using the XcvrSelect[1:0] bits in the Function Control register.
DS00002646A-page 60
2009-2018 Microchip Technology Inc.
USB334x
6.7.2
USB AUDIO MODE (USB3341 and USB3346)
When the USB334x is powered in Synchronous Mode, the Audio switches can be enabled by asserting the SpkLeftEn,
or SpkRightEn bits in the Carkit Control register. After the register write is complete, the USB334x will immediately
enable or disable the audio switch. Then the Link can set the CarkitMode bit in the Interface Control register. The
SpkLeftEn, or SpkRightEn bits must be written before the CarkitMode bit.
TABLE 6-12:
ULPI REGISTER PROGRAMMING EXAMPLE TO ENTER AUDIO MODE
R/W
Address
(HEX)
Value
(HEX)
Description
Result
W
04
48
Configure Non-Driving mode
OpMode=01
W
19
30
Enable Audio connections
SpkrRightEn=1, SpkrLeftEn=1
W
07
04
Enable carkit mode
CarkitMode=1
After the CarkitMode bit is set, the ULPI interface will become redefined as described in Table 6-10.
6.8
RID Converter Operation
The RID converter is designed to read the value of the ID resistance to ground and report back its value through the
ULPI interface.
When a resistor to ground is applied to the ID pin the state of the IdGnd comparator will change from a 1 to a 0 as
described in Section 5.7.1, "ID Resistor Detection," on page 32. If the USB334x is in ULPI mode, an RXCMD will be
generated with bit 6 low. If the USB334x is in Low Power Mode (or one of the other non-ULPI modes), the DATA[3] interrupt signal will go high.
After the USB334x has detected the change of state on the ID pin, the RID converter can be used to determine the value
of ID resistance. To start a ID resistance measurement, the RidConversionStart bit is set in the Vendor Rid Conversion
register.
The Link can use one of two methods to determine when the RID Conversion is complete. One method is polling the
RidConversionStart bit as described in Section 7.1.3.4, "Vendor Rid Conversion," on page 74. The preferred method is
to set the RidIntEn bit in the Vendor Rid Conversion register. When RidIntEn is set, an RXCMD will be generated after
the RID conversion is complete. As described in Table 6-3, the alt_int bit of the RXCMD will be set.
After the RID Conversion is complete, the Link can read RidValue from the Vendor Rid Conversion register.
6.8.1
HEADSET AUDIO MODE
This mode is designed to allow a user to view the status of several signals while using an analog Audio headset with a
USB connector. This mode is provided as an alternate mode to the CarKit Mode defined in Section 6.7, "Carkit Mode,"
on page 59. In the CarKit mode the Link is unable to view the source of the interrupt on ID. For the Link to view the
interrupt on ID the PHY must be returned to synchronous mode so the interrupt can be read. This will force the audio
switches to be deactivated during the PHY start-up which may glitch the audio signals. In addition the Link can not
change the resistance on the ID pin without starting up the PHY to access the ULPI registers.
The Headset Audio Mode is entered by writing to the Headset Audio Mode register, and allows the Link access to the
state of the VBUS and ID pins during audio without having to break the audio connection. The Headset Audio mode
also allows for the Link to change the resistance on the ID pin to change the audio device attached from mono to stereo.
2009-2018 Microchip Technology Inc.
DS00002646A-page 61
USB334x
TABLE 6-13:
Signal
PIN DEFINITIONS IN HEADSET AUDIO MODE
Connected to
Direction
Description
SessVld
DATA[0]
OUT
Output of SessVld comparator
VbusVld
DATA[1]
OUT
Output of VbusVld Comparator (interrupt must be enabled)
IdGndDrv
DATA[2]
IN
Drives ID pin to ground when asserted
0b: Not connected
1b: Connects ID to ground.
DATA[3]
OUT
Driven low
IdGround
DATA[4]
OUT
Asserted when the ID pin is grounded.
0b: ID pin is grounded
1b: ID pin is floating
IdFloat
DATA[5]
OUT
Asserted when the ID pin is floating. IdPullup or
Id_pullup330 must be enabled.
IdFloatRise and IdFloatFall must be enabled.
IdPullup330
DATA[6]
IN
When enabled a 330kΩ pullup is applied to the ID pin. This
bit will also change the trip point of the IdGnd comparator
to the value shown in Table 4-9.
0b: Disables the pull-up resistor
1b: Enables the pull-up resistor
IdPullup
DATA[7]
IN
Connects the 100kΩ pull-up resistor from the ID pin to
VDD3.3
0b: Disables the pull-up resistor
1b: Enables the pull-up resistor
Exiting Headset Audio Mode is the same as exiting Low Power Mode as described in Section 6.5.2, "Exiting Low Power
Mode," on page 57. The RESETB pin can also be pulsed low to reset the USB334x and return to Synchronous Mode.
DS00002646A-page 62
2009-2018 Microchip Technology Inc.
USB334x
7.0
ULPI REGISTER MAP
7.1
ULPI Register Array
The USB334x PHY implements all of the ULPI registers detailed in the ULPI revision 1.1 specification. The complete
USB334x ULPI register set is shown in Table 7-1. All registers are 8 bits. This table also includes the default state of
each register upon POR or de-assertion of RESETB, as described in Section 5.6.2, "Power On Reset (POR)," on
page 31. The RESET bit in the Function Control Register does not reset the bits of the ULPI register array. The Link
should not read or write to any registers not listed in this table.
The USB334x supports extended register access. The immediate register set (00-3Fh) can be accessed through either
a immediate address or an extended register address.
TABLE 7-1:
ULPI REGISTER MAP
Register Name
Default
State
Address (6bit)
Read
Write
Set
Clear
Vendor ID Low
24h
00h
-
-
-
Vendor ID High
04h
01h
-
-
-
Product ID Low
09h
02h
-
-
-
Product ID High
00h
03h
-
-
-
Function Control
41h
04-06h
04h
05h
06h
Interface Control
00h
07-09h
07h
08h
09h
OTG Control
06h
0A-0Ch
0Ah
0Bh
0Ch
USB Interrupt Enable Rising
1Fh
0D-0Fh
0Dh
0Eh
0Fh
USB Interrupt Enable Falling
1Fh
10-12h
10h
11h
12h
USB Interrupt Status (Note 7-1)
00h
13h
-
-
-
USB Interrupt Latch
00h
14h
-
-
-
Debug
00h
15h
-
-
-
Scratch Register
00h
16-18h
16h
17h
18h
Carkit Control
00h
19-1Bh
19h
1Ah
1Bh
Reserved
00h
Carkit Interrupt Enable
00h
1D-1Fh
1Dh
1Eh
1Fh
Carkit Interrupt Status
00h
20h
-
-
-
Carkit Interrupt Latch
00h
21h
-
-
-
Reserved
00h
HS Compensation Register
00h
31h
31h
-
-
USB-IF Charger Detection
00h
32h
32h
-
-
Headset Audio Mode
00
33
33
-
-
Reserved
00h
2009-2018 Microchip Technology Inc.
1Ch
22-30h
34-35h
DS00002646A-page 63
USB334x
TABLE 7-1:
ULPI REGISTER MAP (CONTINUED)
Default
State
Register Name
Address (6bit)
Read
Write
Set
Clear
Vendor Rid Conversion
00h
36-38h
36h
37h
38h
USB IO & Power Management
04h
39-3Bh
39h
3Ah
3Bh
Reserved
00h
Note 7-1
7.1.1
3C-3Fh
Dynamically updates to reflect current status of interrupt sources.
ULPI REGISTER SET
The following registers are used for the ULPI interface.
7.1.1.1
Vendor ID Low
Address = 00h (read only)
Field Name
Vendor ID Low
7.1.1.2
Bit
Access
Default
7:0
rd
24h
Bit
Access
Default
7:0
rd
04h
Bit
Access
Default
7:0
rd
09h
Bit
Access
Default
7:0
rd
00h
Description
Microchip Vendor ID
Vendor ID High
Address = 01h (read only)
Field Name
Vendor ID High
7.1.1.3
Description
Microchip Vendor ID
Product ID Low
Address = 02h (read only)
Field Name
Product ID Low
7.1.1.4
Description
Microchip Product ID
Product ID High
Address = 03h (read only)
Field Name
Product ID High
DS00002646A-page 64
Description
Microchip Product ID
2009-2018 Microchip Technology Inc.
USB334x
7.1.1.5
Function Control
Address = 04-06h (read), 04h (write), 05h (set), 06h (clear)
Field Name
Bit
Access
Default
1:0
rd/w/s/c
01b
Selects the required transceiver speed.
00b: Enables HS transceiver
01b: Enables FS transceiver
10b: Enables LS transceiver
11b: Enables FS transceiver for LS packets (FS
preamble automatically pre-pended)
2
rd/w/s/c
0b
Controls the DP and DM termination depending on
XcvrSelect, OpMode, DpPulldown, and DmPulldown.
The DP and DM termination is detailed in Table 5-1.
4:3
rd/w/s/c
00b
Selects the required bit encoding style during
transmit.
00b: Normal Operation
01b: Non-Driving
10b: Disable bit-stuff and NRZI encoding
11b: Reserved
Reset
5
rd/w/s/c
0b
Active high transceiver reset. This reset does not
reset the ULPI interface or register set. Automatically
clears after reset is complete.
SuspendM
6
rd/w/s/c
1b
Active low PHY suspend. When cleared the PHY will
enter Low Power Mode as detailed in Section 6.5,
"Low Power Mode," on page 55. Automatically set
when exiting Low Power Mode.
LPM Enable
7
rd/w/s/c
0b
When enabled the PLL start-up time is shortened to
allow fast start-up for LPM. The reduced PLL start-up
time is achieved by bypassing the VCO process
compensation which was done on initial start-up.
XcvrSelect[1:0]
TermSelect
OpMode
7.1.1.6
Description
Interface Control
Address = 07-09h (read), 07h (write), 08h (set), 09h (clear)
Field Name
Bit
Access
Default
Description
6-pin FsLsSerialMode
0
rd/w/s/c
0b
When asserted the ULPI interface is redefined to the
6-pin Serial Mode. The PHY will automatically clear
this bit when exiting serial mode.
3-pin FsLsSerialMode
1
rd/w/s/c
0b
When asserted the ULPI interface is redefined to the
3-pin Serial Mode. The PHY will automatically clear
this bit when exiting serial mode.
CarkitMode
2
rd/w/s/c
0b
When asserted the ULPI interface is redefined to the
Carkit interface. The PHY will automatically clear this
bit when exiting Carkit Mode.
2009-2018 Microchip Technology Inc.
DS00002646A-page 65
USB334x
Field Name
Bit
Access
Default
Description
ClockSuspendM
3
rd/w/s/c
0b
Enables Link to turn on 60 MHz CLKOUT in Serial
Mode or Carkit Mode.
0b: Disable clock in serial or Carkit Mode.
1b: Enable clock in serial or Carkit Mode.
AutoResume
4
rd/w/s/c
0b
Only applicable in Host mode. Enables the PHY to
automatically transmit resume signaling. This
function is detailed in Section 6.4.1.4, "Host Resume
K," on page 53.
IndicatorComplement
5
rd/w/s/c
0b
Inverts the EXTVBUS signal. This function is detailed
in Section 5.7.2, "VBUS Monitoring and VBUS
Pulsing," on page 35.
Note:
IndicatorPassThru
6
rd/w/s/c
0b
Disables and’ing the internal VBUS comparator with
the EXTVBUS signal when asserted. This function is
detailed in Section 5.7.2, "VBUS Monitoring and
VBUS Pulsing," on page 35.
Note:
InterfaceProtectDisable
7.1.1.7
7
rd/w/s/c
0b
The EXTVBUS signal is always high on the
USB334x.
The EXTVBUS signal is always high on the
USB334x.
Used to disable the integrated STP pull-up resistor
used for interface protection. This function is detailed
in Section 6.5.4, "Interface Protection," on page 57.
OTG Control
Address = 0A-0Ch (read), 0Ah (write), 0Bh (set), 0Ch (clear)
Field Name
Bit
Access
Default
Description
IdPullup
0
rd/w/s/c
0b
Connects a 100 kΩ pull-up resistor from the ID pin to
VDD33
0b: Disables the pull-up resistor
1b: Enables the pull-up resistor
DpPulldown
1
rd/w/s/c
1b
Enables the 15 kΩ pull-down resistor on DP.
0b: Pull-down resistor not connected
1b: Pull-down resistor connected
DmPulldown
2
rd/w/s/c
1b
Enables the 15 kΩ pull-down resistor on DM.
0b: Pull-down resistor not connected
1b: Pull-down resistor connected
DischrgVbus
3
rd/w/s/c
0b
This bit is only used during SRP. Connects a resistor
from VBUS to ground to discharge VBUS.
0b: disconnect resistor from VBUS to ground
1b: connect resistor from VBUS to ground
ChrgVbus
4
rd/w/s/c
0b
This bit is only used during SRP. Connects a resistor
from VBUS to VDD33 to charge VBUS above the
SessValid threshold.
0b: disconnect resistor from VBUS to VDD33
1b: connect resistor from VBUS to VDD33
DS00002646A-page 66
2009-2018 Microchip Technology Inc.
USB334x
Field Name
Bit
Access
Default
Description
DrvVbus
5
rd/w/s/c
0b
Enables external 5 volt supply to drive 5 volts on
VBUS. This signal is or’ed with DrvVbusExternal.
0b: Do not drive Vbus.
1b: Drive Vbus
DrvVbusExternal
6
rd/w/s/c
0b
Enables external 5 volt supply to drive 5 volts on
VBUS. This signal is or’ed with DrvVbus.
0b: Do not drive Vbus
1b: Drive Vbus
UseExternalVbus
Indicator
7
rd/w/s/c
0b
Tells the PHY to use an external VBUS over-current
or voltage indicator. This function is detailed in
Section 5.7.2, "VBUS Monitoring and VBUS Pulsing,"
on page 35.
0b: Use the internal VbusValid comparator
1b: Use the EXTVBUS input as for VbusValid signal.
Note:
7.1.1.8
The EXTVBUS signal is always high on the
USB334x.
USB Interrupt Enable Rising
Address = 0D-0Fh (read), 0Dh (write), 0Eh (set), 0Fh (clear)
Field Name
Bit
Access
Default
Description
HostDisconnect Rise
0
rd/w/s/c
1b
Generate an interrupt event notification when
Hostdisconnect changes from low to high. Applicable
only in host mode.
VbusValid Rise
1
rd/w/s/c
1b
Generate an interrupt event notification when
Vbusvalid changes from low to high.
SessValid Rise
2
rd/w/s/c
1b
Generate an interrupt event notification when
SessValid changes from low to high.
SessEnd Rise
3
rd/w/s/c
1b
Generate an interrupt event notification when
SessEnd changes from low to high.
IdGnd Rise
4
rd/w/s/c
1b
Generate an interrupt event notification when IdGnd
changes from low to high.
7:5
rd
0h
Read only, 0.
Reserved
7.1.1.9
USB Interrupt Enable Falling
Address = 10-12h (read), 10h (write), 11h (set), 12h (clear)
Field Name
Bit
Access
Default
Description
HostDisconnect Fall
0
rd/w/s/c
1b
Generate an interrupt event notification when
Hostdisconnect changes from high to low. Applicable
only in host mode.
VbusValid Fall
1
rd/w/s/c
1b
Generate an interrupt event notification when
Vbusvalid changes from high to low.
SessValid Fall
2
rd/w/s/c
1b
Generate an interrupt event notification when
SessValid changes from high to low.
2009-2018 Microchip Technology Inc.
DS00002646A-page 67
USB334x
Field Name
Bit
Access
Default
SessEnd Fall
3
rd/w/s/c
1b
Generate an interrupt event notification when
SessEnd changes from high to low.
IdGnd Fall
4
rd/w/s/c
1b
Generate an interrupt event notification when IdGnd
changes from high to low.
Reserved
7:5
rd
0h
Read only, 0.
7.1.1.10
Description
USB Interrupt Status
Address = 13h (read only)
This register dynamically updates to reflect current status of interrupt sources.
Field Name
Bit
Access
Default
Description
HostDisconnect
0
0b
Current value of the UTMI+ HS Hostdisconnect
output. Applicable only in host mode.
VbusValid
1
0b
Current value of the UTMI+ Vbusvalid output. If
VbusValid Rise and VbusValid Fall are set this
register will read 0.
SessValid
2
0b
Current value of the UTMI+ SessValid output. This
register will always read the current status of the
Session Valid comparator regardless of the
SessValid Rise and SessValid Fall settings.
SessEnd
3
0b
Current value of the UTMI+ SessEnd output. If
SessEnd Rise and SessEnd Fall are set this register
will read 0.
IdGnd
4
0b
Current value of the UTMI+ IdGnd output.
7:5
0h
Read only, 0.
Reserved
Note:
rd
(read
only)
The default value is only valid after POR. When the register is read it will match the current status of the
comparators at the moment the register is read.
DS00002646A-page 68
2009-2018 Microchip Technology Inc.
USB334x
7.1.1.11
USB Interrupt Latch
Address = 14h (read only with auto clear)
Field Name
Bit
Access
Default
Description
HostDisconnect Latch
0
0b
Set to 1b by the PHY when an unmasked event
occurs on Hostdisconnect. Cleared when this register
is read. Applicable only in host mode.
VbusValid Latch
1
0b
Set to 1b by the PHY when an unmasked event
occurs on VbusValid. Cleared when this register is
read.
SessValid Latch
2
0b
Set to 1b by the PHY when an unmasked event
occurs on SessValid. Cleared when this register is
read.
SessEnd Latch
3
0b
Set to 1b by the PHY when an unmasked event
occurs on SessEnd. Cleared when this register is
read.
IdGnd Latch
4
0b
Set to 1b by the PHY when an unmasked event
occurs on IdGnd. Cleared when this register is read.
0h
Read only, 0.
rd
(Note 7-2)
Reserved
7:5
Note 7-2
rd: Read Only with auto clear.
7.1.1.12
rd
Debug
Address = 15h (read only)
Field Name
Bit
Access
Default
Linestate[1:0]
1:0
rd
00b
Reserved
7:2
rd
000000b
7.1.1.13
Description
Contains the current value of Linestate[1:0].
Read only, 0.
Scratch Register
Address = 16-18h (read), 16h (write), 17h (set), 18h (clear)
Field Name
Scratch
Bit
Access
Default
7:0
rd/w/s/c
00h
2009-2018 Microchip Technology Inc.
Description
Empty register byte for testing purposes. Software
can read, write, set, and clear this register and the
PHY functionality will not be affected.
DS00002646A-page 69
USB334x
7.1.2
CARKIT CONTROL REGISTERS
The following registers are used to set-up and enable the USB UART and USB Audio functions.
7.1.2.1
Carkit Control
Address = 19-1Bh (read), 19h (write), 1Ah (set), 1Bh (clear)
This register is used to program the USB334x into and out of the Carkit Mode. When entering the UART mode the Link
must first set the desired TxdEn and the RxdEn bits and then transition to Carkit Mode by setting the CarkitMode bit in
the Interface Control Register. When RxdEn is not set then the DATA[1] pin is held to a logic high.
Field Name
Bit
Access
Default
CarkitPwr
0
rd
0b
Read only, 0.
IdGndDrv
1
rd/w/s/c
0b
Drives ID pin to ground
TxdEn
2
rd/w/s/c
0b
Connects UART TXD (DATA[0]) to DM
RxdEn
3
rd/w/s/c
0b
Connects UART RXD (DATA[1]) to DP
SpkLeftEn
4
rd/w/s/c
0b
Connects DM pin to SPK_L pin
SpkRightEn
5
rd/w/s/c
0b
Connects DP pin to SPK_R pin. See Note below.
MicEn
6
rd/w/s/c
0b
Connects DP pin to SPK_R pin. See Note below.
CarkitDataMC
7
rd/w/s/c
0b
When set the UPLI DATA[2] pin is changed from a
driven 0 to tri-state, when carkit mode is entered.
Note:
Description
If SpkRightEn or MicEn are asserted the DP pin will be connected to SPK_R. To disconnect the DP pin
from the SPK_R pin both SpkrRightEn and MicEn must be set to de-asserted.
If using USB UART mode, the UART data will appear at the SPK_L and SPK_R pins if the corresponding SpkLeftEn,
SpkRightEn, or MicEn switches are enabled.
If using USB Audio the TxdEn and RxdEn bits should not be set when the SpkLeftEn, SpkRightEn, or MicEn switches
are enabled. The USB single-ended receivers described in Section 5.2.1, "USB Transceiver," on page 25 are disabled
when either SpkLeftEn, SpkRightEn, or MicEn are set.
7.1.2.2
Carkit Interrupt Enable
Address = 1D-1Fh (read), 1Dh (write), 1Eh (set), 1Fh (clear)
Field Name
Bit
Access
Default
Description
IdFloatRise
0
rd/w/s/c
0b
When enabled an interrupt will be generated on the
alt_int of the RXCMD byte when the ID pin transitions
from non-floating to floating. The IdPullup bit in the
OTG Control register should be set.
IdFloatFall
1
rd/w/s/c
0b
When enabled an interrupt will be generated on the
alt_int of the RXCMD byte when the ID pin transitions
from floating to non-floating. The IdPullup bit in the
OTG Control register should be set.
VdatDetIntEn
2
rd/w/s/c
0b
When enabled an interrupt will be generated on the
alt_int of the RXCMD byte when the VDAT_DET
Comparator changes state.
DS00002646A-page 70
2009-2018 Microchip Technology Inc.
USB334x
Field Name
Bit
Access
Default
Description
CarDpRise
3
rd
0b
Not Implemented. Reads as 0b.
CarDpFall
4
rd
0b
Not Implemented. Reads as 0b.
RidIntEn
5
rd/w/s/c
0b
When enabled an interrupt will be generated on the
alt_int of the RXCMD byte when RidConversionDone
bit is asserted.
Note:
This register bit is or’ed with the RidIntEn bit
of the Vendor Rid Conversion register
described in Section 7.1.3.4, "Vendor Rid
Conversion," on page 74.
Reserved
6
rd/w/s/c
0b
Read only, 0.
Reserved
7
rd
0b
Read only, 0.
Bit
Access
Default
Description
IdFloat
0
rd
0b
Asserted when the ID pin is floating. IdPullup must be
enabled.
VdatDet
1
rd
0b
VDAT_DET Comparator output
0b: No voltage is detected on DP
1b: Voltage detected on DP, IdatSinkEn must be set
to 1.
7.1.2.3
Carkit Interrupt Status
Address = 20h (read only)
Field Name
Note:
CarDp
RidValue
VdatDet can also be read from the USB-IF
Charger Detection register described in
Section 7.1.3.3, "Headset Audio Mode," on
page 74.
2
rd
0b
Not Implemented. Reads as 0b.
5:3
rd
000b
Conversion value of Rid resistor
000: 0Ω
001: 75Ω
010: 102 KΩ
011: 200 KΩ
100: Reserved
101: ID floating
111: Error
Note:
2009-2018 Microchip Technology Inc.
RidValue can also be read from the Vendor
Rid Conversion register described in
Section 7.1.3.4, "Vendor Rid Conversion,"
on page 74.
DS00002646A-page 71
USB334x
Field Name
RidConversionDone
Bit
Access
Default
Description
6
rd
0b
Automatically asserted by the USB334x when the Rid
Conversion is finished. The conversion will take
282uS. This bit will auto clear when the RidValue is
read from the Rid Conversion Register. Reading the
RidValue from the Carkit Interrupt Status register will
not clear either RidConversionDone status bit.
Note:
Reserved
7.1.2.4
7
rd
0b
RidConversionDone can also be read from
the Vendor Rid Conversion register
described in Section 7.1.3.4, "Vendor Rid
Conversion," on page 74.
Read only, 0.
Carkit Interrupt Latch
Address = 21h (read only with auto-clear)
Field Name
Bit
Access
Default
Description
IdFloat Latch
0
rd
(Note 7-3)
0b
Asserted if the state of the ID pin changes from nonfloating to floating while the IdFloatRise bit is enabled
or if the state of the ID pin changes from floating to
non-floating while the IdFloatFall bit is enabled.
VdatDet Latch
1
rd
0b
If VdatDetIntEn is set and the VdatDet bit changes
state, this bit will be asserted.
CarDp Latch
2
rd
0b
Not Implemented. Reads as 0b.
RidConversionLatch
3
rd
(Note 7-3)
0b
If RidIntEn is set and the state of the
RidConversionDone bit changes from a 0 to 1 this bit
will be asserted.
Reserved
7:4
rd
0000b
Note 7-3
rd: Read Only with auto clear
7.1.3
Read only, 0.
VENDOR REGISTER ACCESS
The vendor specific registers include the range from 30h to 3Fh. These can be accessed by the ULPI immediate register
read / write.
7.1.3.1
HS Compensation Register
Address = 31h (read / write)
The USB334x is designed to meet the USB specifications and requirements when the DP and DM signals are properly
designed on the PCB. The DP and DM trace impedance should be 45Ω single ended and 90Ω differential. In cases
where the DP and DM traces are not able to meet these requirements the HS Compensation register can be used to
compensate for the losses in signal amplitude.
DS00002646A-page 72
2009-2018 Microchip Technology Inc.
USB334x
Field Name
Bit
Access
Default
Description
VariSense
1:0
rd/w
00b
Used to lower the threshold of the squelch detector.
00: 100% (default)
01: 83%
10: 66.7%
11: 50%
Reserved
2
rd
0b
Read only, 0.
Reserved
3
rd
0b
Read only, 0.
PHYBoost
6:4
rd/w
000b
Reserved
7
rd
0b
7.1.3.2
Used to change the output voltage of the Hi-Speed
transmitter
000: Nominal
001: +3.7%
010: +7.4%
011: +11.0%
100: +14.7%
101: +18.3%
110: +22.0%
111: +25.7%
Read only, 0.
USB-IF Charger Detection
Address = 32h (read / write)
Field Name
Bit
Access
Default
VDatSrcEn
0
rd/w
0
VDAT_SRC voltage enable
0b: Disabled
1b: Enabled
IDatSinkEn
1
rd/w
0
IDAT_SINK current sink and VDAT_DET comparator
enable
0b: Disabled, VDAT_DET = 0.
1b: Enabled
ContactDetectEn
2
rd/w
0
IDP_SRC Enable
0b: Disabled
1b: Enabled
HostChrgEn
3
rd/w
0
Enable Charging Host Port Mode.
0b: Portable Device
1b: Charging Host Port. When the charging host port
bit is set the connections of VDAT_SRC, IDAT_SINK,
IDP_SRC, and VDAT_DET are reversed between DP
and DM.
2009-2018 Microchip Technology Inc.
Description
DS00002646A-page 73
USB334x
Field Name
VdatDet
Bit
Access
Default
Description
4
rd
0
VDAT_DET Comparator output. IdatSinkEn must be set
to 1 to enable the comparator.
0b: No voltage is detected on DP or Linestate[1:0] is
not equal to 00b.
1b: Voltage detected on DP, and Linestate[1:0] = 00b.
Note:
Reserved
Note:
7.1.3.3
5-7
rd
VdatDet can also be read from the Carkit
Interrupt Status register described in
Section 7.1.2.3, "Carkit Interrupt Status," on
page 71.
Read only, 0.
The charger detection should be turned off before beginning USB operation. USB-IF Charger Detection
Bits 2:0 should be set to 000b.
Headset Audio Mode
Address = 33h (read / write)
Field Name
Bit
Access
Default
Description
HeadsetAudioEn
3:0
rd/w
0000b
When this field is set to a value of ‘1010’, the Headset Audio Mode is enabled as described in Section
6.8.1, "Headset Audio Mode," on page 61.
Reserved
7:4
rd
0h
7.1.3.4
Read only, 0.
Vendor Rid Conversion
Address = 36-38h (read), 36h (write), 37h (set), 38h (clear)
Field Name
RidValue
Bit
Access
Default
2:0
rd/w
000b
Description
Conversion value of Rid resistor
000: 0Ω
001: 75Ω
010: 100 KΩ
011: 200 KΩ
100: 440 KΩ
101: ID floating
111: Error
Note:
RidConversionDone
3
rd
(Note 7-4)
0b
Automatically asserted by the USB334x when the Rid
Conversion is finished. The conversion will take
282uS. This bit will auto clear when the RidValue is
read from the Rid Conversion Register. Reading the
RidValue from the Carkit Interrupt Status Register will
not clear either RidConversionDone status bit.
Note:
DS00002646A-page 74
RidValue can also be read from the Carkit
Interrupt Status Register.
RidConversionDone can also be read from
the Carkit Interrupt Status Register.
2009-2018 Microchip Technology Inc.
USB334x
Field Name
Bit
Access
Default
Description
RidConversionStart
4
rd/w/s/c
0b
When this bit is asserted either through a register
write or set, the Rid converter will read the value of
the ID resistor. When the conversion is complete this
bit will auto clear.
Reserved
5
rd/w/s/c
0b
This bit must remain at 0.
RidIntEn
6
rd/w/s/c
0b
When enabled an interrupt will be generated on the
alt_int of the RXCMD byte when RidConversionDone
bit is asserted.
Note:
Reserved
7
Note 7-4
7.1.3.5
rd
0b
This register bit is or’ed with the RidIntEn bit
of the Carkit Interrupt Status register.
Read only, 0.
rd: Read Only with auto clear.
USB IO & Power Management
Address = 39-3Bh (read), 39h (write), 3Ah (set), 3Bh (clear)
Field Name
Bit
Access
Default
Reserved
0
rd/w/s/c
0b
Read only, 0.
SwapDP/DM
1
rd/w/s/c
0b
When asserted, the DP and DM pins of the USB
transceiver are swapped. This bit can be used to
prevent crossing the DP/DM traces on the board. In
UART mode, it swaps the routing to the DP and DM
pins. In USB Audio Mode, it does not affect the
SPK_L and SPK_R pins.
3:2
rd/w/s/c
01b
Controls the output voltage of the VBAT to VDD33
regulator in UART mode. When the PHY is switched
from USB mode to UART mode regulator output will
automatically change to the value specified in this
register when TxdEn is asserted.
00: 3.3V
01: 3.0V (default)
10: 2.75V
11: 2.5V
UART RegOutput
Description
Note:
When in USB Audio Mode the regulator will
remain at 3.3V. When using this register it is
recommended that the Link exit UART
mode by using the RESETB pin.
ChargerPullupEnDP
4
rd/w/s/c
0b
Enables the RCD Pull-up resistor on the DP pin. (The
pull-up is automatically enabled in UART mode)
ChargerPullupEnDM
5
rd/w/s/c
0b
Enables the RCD Pull-up resistor on the DM pin. (The
pull-up is automatically enabled in UART mode)
2009-2018 Microchip Technology Inc.
DS00002646A-page 75
USB334x
Field Name
USB RegOutput
DS00002646A-page 76
Bit
Access
Default
Description
7:6
rd/w/s/c
00b
Controls the output voltage of the VBAT to VDD33
regulator in USB mode. When the PHY is in
Synchronous Mode, Serial Mode, or Low Power
Mode, the regulator output will be the value specified
in this register.
00: 3.3V (default)
01: 3.0V
10: 2.75V
11: 2.5V
2009-2018 Microchip Technology Inc.
USB334x
8.0
APPLICATION NOTES
8.1
Application Diagram
The USB334x requires few external components as shown in the application diagrams. The USB 2.0 Specification
restricts the voltage at the VBUS pin to a maximum value of 5.25V. In some applications, the voltage will exceed this
limit, so the USB334x provides an integrated over voltage protection circuit. The over voltage protection circuit works
with an external resistor (RVBUS) to lower the voltage at the VBUS pin.
TABLE 8-1:
REFERENCE
DESIGNATOR
COMPONENT VALUES IN APPLICATION DIAGRAMS
VALUE
DESCRIPTION
COUT
See Table 4-12
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