Si3484
64-P O RT P O E P OWER M ANAGEMENT C ONTROLLER
Features
Pin Assignments
INT
TX
RX
NSS
RSVD
MOSI
19
18 SDA
2
17 SCL
GND
3
VDD
4
RST
5
14
RSVD
6
13 PSLCT
9
11
12
RSVD
PS3
PS2
PS1
RSVD
Top View
(Pads on Bottom of Package )
10
Power over Ethernet Endpoint
Industrial automation systems
switches and Midspans
Networked audio
Supports high-power PDs, such as: IP Phone Systems and iPBXs
zPan/Tilt/Zoom security cameras
zWireless Access Points
zSecurity and RFID systems
1
SCK
8
MISO
7
Applications
20
21
22
24-Pin QFN
23
Supports classification-based and
LLDP power negotiation
Supports individual port priority and
port configuration
Supports Power supply status from
up to 3 power supplies
24-pin Quad flat pack package
z4x4 mm PCB footprint; RoHS
complaint
Extended temperature operating
range (–40 to +85 °C)
24
Enables use of smaller power
supplies for up to 64-port PoE
systems with Si3459 and Si3454
PSE Controller ICs
Can operate with or without a host
Configuration save capability
Pin-selectable SPI or UART interface
Pin-selectable UART data rate
Fully-compliant with IEEE 802.3-AT
Types I and II
RESET_PSE
16 BAUD0
15 BAUD1
RSVD
See "5. Pin Descriptions" on page 45.
Description
The Si3484 is a power manager intended for use with the Si3459 Power over
Ethernet (PoE) Power Sourcing Equipment (PSE) controllers for power
management of up to 64 ports with three power sources.
The Si3459 is capable of delivering over 30 W per port, which means that, in a 24or 48-port system, a very large power supply would have to be used to avoid
overload. Typically, not all ports are used at full power; so, a smaller power supply
can be used along with the Si3484 power management controller.
Use of the Si3484 power manager greatly simplifies system implementation of
power management. The Si3484 power management controller is programmed
via a SPI or UART interface to set the system power supply capacity, the port
power configuration (Type 1: 15.4 W, or high-power Type 2: 30 W) ports, the port
priority, the detection timing (Alternative A or Alternative B), and the fault recovery
protocol. Once programmed, the configuration data can be saved, and the Si3484
can work without host intervention. Port and overall status information is available
and continuously updated.
The Si3484 uses the real-time overload and current monitoring capability of the
Si3459 to manage power shared among up to 64 ports. Power management is
selectable between grant-based or consumption-based algorithms in order to
supply power to the greatest number of ports.
In high-reliability systems, multiple power supplies are often connected to provide
redundancy, which further increases the power supply monitoring requirements.
The Si3484 can manage up to three power supplies automatically, enabling or
disabling ports in priority order.
Rev. 1.0 11/17
Copyright © 2017 by Silicon Laboratories
Si3484
Si3484
Functional Block Diagram
Si3484 Application Diagram
MCU or
Host Controller
UART or SPI
Si8631
Digital Isolator
Power Supply Present
Select
UART or SPI
Si3484 Power
Management
Controller
Power Supply 1
Power Supply 2
UART
Baud Rate
I 2C
Power Supply 3
Power
Si3459 Port Controller
PD
2
PD
PD
PD
PD
PD
PD
Si3459 Port Controller
PD
PD
PD
PD
PD
PD
Rev. 1.0
PD
PD
Si3459 Port Controller
PD
PD
PD
PD
PD
PD
PD
PD
PD
Si3484
TABLE O F C ONTENTS
Section
Page
1. Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
2. Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
2.1. Host Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
2.2. Hardware Only Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
3. Serial Packet Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
3.1. Packet Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.2. SPP Error Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4. Power Manager API . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.1. System Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.2. Port Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
4.3. System Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
4.4. Port Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
4.5. System Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
4.6. Port Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
4.7. Power Supply Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
4.8. Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
4.9. Return Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
5. Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
6. Ordering Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
7. Package Outline: 24-Pin QFN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
8. PCB Land Pattern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
9. Top Marking Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Rev. 1.0
3
Si3484
1. Electrical Specifications
Table 1. Recommended Operating Conditions
Description
Symbol
Test Condition
Min
Typ
Max
Unit
TA
No airflow
–40
—
85
°C
VDD
All operating modes
2.7
—
3.6
V
Min
Typ
Max
Unit
Ambient Temperature
under Bias
–55
—
125
°C
Storage Temperature
–65
—
150
°C
–0.3
—
5.8
V
–0.3
—
4.2
V
Operating Temperature
Range
VDD Supply Voltage
Table 2. Absolute Maximum Ratings
Parameter
Test Condition
Voltage on any I/O with
Respect to GND
VDD>2.2 V
Voltage on VDD with
Respect to GND
Note: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a
stress rating only and functional operation of the devices at those or any other conditions above those indicated in the
operation listings of this specification is not implied. Exposure to maximum rating conditions for extended periods may
affect device reliability.
Table 3. Electrical Characteristics
Parameter
Symbol
Test Condition
Min
Typ
Max
Unit
Input High
VIH
2.0
—
—
V
Input Low
VIL
—
—
0.8
V
Input Leakage Current
IIL
Input pins:
RST, SCK, MOSI, NSS,
RX, PSn, BAUDn,
SLCTIN, SCL, SDA
—
—
±1
uA
Output Low
(MOSI, TX, SCL, and SDA)
VOL
IOL = 8.5 mA
—
—
0.6
V
Output High
(MOSI, TX)
VOH
IOH = –3 mA
VDD–0.7
—
—
V
VDD Current
IDD
VDD = 3.0 V*
VDD = 3.6 V*
—
—
8.6
12.1
mA
*Note: VDD = 2.7 to 3.6 V, –40 to 85 °C unless otherwise noted.
4
Rev. 1.0
Si3484
Table 4. Timing Requirements
Parameter
Symbol
Min
Max
Unit
NSS Falling to First SCK Edge
TSE
84
—
ns
Last SCK Edge to NSS Rising
TSD
84
—
ns
NSS Falling to MISO Valid
TSEZ
—
168
ns
NSS Rising to MISO High Z
TSDZ
—
168
ns
SCK High Time
TCKH
210
—
ns
SCK Low Time
TCKL
210
—
ns
MOSI Valid to SCK Sample Edge
TSIS
84
—
ns
SCK Sample Edge to MOSI Change
TSIH
84
—
ns
SCK Shift Edge to MISO Change
TSCH
—
168
ns
Maximum SPI Clock Speed
FMAX
—
1
MHz
Deviation of Tx Transmit Speed from Pin-programmed Value
ǻFTx
–3
+3
%
Deviation of Rx receive Speed from Pin-programmed Value
ǻFRx
–4
+4
%
SPI Timing Requirements (See Figure 1)
UART Requirements (See Figure 2)
TSE
TCKH
TCKL
TSD
SCK
TSIH
MOSI
MSB
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
TSIS
MISO
MSB
TSEZ
TSCH
TSDZ
NSS
Figure 1. SPI Timing Diagram
MARK
SPACE
START
BIT
D0
D1
D2
D3
D4
D5
D6
D7
STOP
BIT
BIT TIMES
BIT SAMPLING
Figure 2. UART Timing Diagram
Rev. 1.0
5
Si3484
2. Functional Description
The Si3484 Power Management Controller takes the role of the central controller in a Silicon Labs Power over
Ethernet (PoE) system. In a PoE system, power is provided by one or more power supplies and is consumed by
one or more powered devices (PDs). The Si3484 decides which of the PDs can have power and monitors the
amount of power consumed by each.
A host microcontroller unit (MCU) can configure the Si3484 and can query the status of the PDs and the power
supplies. The Si3484 stores its configuration in internal flash memory. A host MCU uses a Universal Asynchronous
Receiver Transmitter (UART) or a Serial Peripheral Interface (SPI) to communicate with the Si3484. Pins on the
Si3484 select which host interface to use and which baud rate to use for the UART interface.
Power supplies may be inserted into bays. The Si3484 supports a system with up to three bays. Power supplies
may be inserted or removed from the bays at any time. Each bay provides a signal to the Si3484 that indicates if a
power supply is present and operational in the bay. The outputs of the power supplies are ganged together to
provide a single power source for the system.
The Si3484 manages a collection of Si3459 Port Controllers. The Si3484 supports a system with up to 8 Si3459s.
Each Si3459 has eight ports; so, a system may have up to 64 ports. The Si3459 performs low-level port functions,
such as detecting and classifying PDs. The Si3484 has a global view of the system and manages power across all
ports.
PDs are connected to ports on the Si3459s. PDs may be connected or disconnected from the ports at any time.
When a PD is connected to a port, then the PD requests power from the port. The Si3484 determines the amount
of power requested from the classification of the PD. If there is enough power remaining, the Si3484 grants the
request; otherwise, the Si3484 denies the request.
The host may configure an optional power limit for each port. A power limit restricts the amount of power that the
Si3484 grants to a port. If a power request is greater than the power limit, the Si3484 does not fully grant the
request, but only grants the amount of the power limit.
The Si3484 supports Link Layer Discovery Protocol (LLDP) agents in the host. An LLDP agent can call a routine in
the Si3484 to dynamically adjust the amount of power granted to a PD during the course of a connection.
Several PDs may be connected to a PoE system. The Si3484 may have granted different amounts of power to
each PD, and each PD may be consuming different amounts of power. If a PD consumes more power than it is
granted (port overload), the Si3484 turns off the PD.
There are two approaches that the Si3484 can take when granting requests for power. The granting policy can be
grant-based or it can be consumption-based.
Figure 3. Powered Devices Example
6
Rev. 1.0
Si3484
Figure 4. Grant Based Power Management
Figure 5. Consumption-Based Power Management
If the granting policy is grant based, then the power remaining for new grants is the total ungranted power. The
power remaining is the total power provided minus the total power granted.
The problem with this approach is that much of the provided power is unused because PDs often do not consume
all of their granted power.
If the granting policy is consumption-based, then the power remaining for new grants is the total unconsumed
power. The power remaining is the total power provided minus the total power consumed (excluding the reserved
power). This approach uses more of the provided power, but there is a possibility that the system may consume
more power than the power provided (system overload).
To avoid system overloads caused by momentary surges in power consumption, the host can specify that a certain
amount of power be held in reserve. The Si3484 does not use the reserved power when granting new requests.
Most power supplies can tolerate a limited amount of overload for a short duration. The host specifies the overload
limit of the power supplies to the Si3484. If a system overload is less than the overload limit, the Si3484 turns off
ports, one at a time in priority order, until the system is no longer overloaded. If a system overload is greater than
the overload limit (severe overload), the Si3484 immediately turns off all low-priority ports. If the system is still
overloaded, the Si3484 turns off additional ports, one at a time in priority order, until the system is no longer
overloaded. A severe overload is usually caused by removing a power supply.
2.1. Host Interface
The Si3484 has a UART interface and an SPI interface for communicating with the host MCU, but only one
interface is used at a time. The PSLCT (protocol select) pin selects which interface is used.
2.1.1. UART Interface
If the PSLCT pin is tied high, then the Si3484 uses the UART interface to communicate with the host MCU. The
Si3484 uses the TX and RX pins to send and receive serial data. The BAUD0 and BAUD1 pins select the baud rate
for the UART interface.
Rev. 1.0
7
Si3484
Table 5. Baud Rates
BAUD1
BAUD0
Baud Rate (bps)
L
L
19200
L
H
38400
H
L
57600
H
H
115200
The UART interface uses eight data bits, no parity, and one stop bit.
2.1.2. SPI Interface
If the PSLCT pin is tied low, then the Si3484 uses the SPI interface to communicate with the host MCU. The
Si3484 is an SPI slave device. Therefore, it receives data on the MOSI pin and sends data on the MISO pin. The
host MCU drives the NSS and SCK pins.
The SPI interface uses an active-high clock (CKPOL = 0). The clock line is low in the idle state, and the leading
edge of the clock goes from low to high. The SPI interface samples the data on the leading edge of the clock
(CKPHA = 0). The SPI interface transfers the most-significant bit first, and the maximum bit rate is 1 Mbps.
2.2. Hardware Only Mode
The host interface (SPI or UART) and the UART baud rate are pin-configured. The Si3484 reads the pin
configuration at power up, and it cannot be changed after power up. The hardware designer only needs to decide
which interface to use and, if UART is selected, which BAUD rate to use.
In general, the host interface must be electrically isolated from the host MCU using an appropriate electrical
isolator for either SPI or UART signals as well as power supply status signals as needed.
The Si3484 backs up its configuration to internal flash memory. Once the Si3484 is configured, it is possible to
disconnect the host interface and use the Si3484 without a host MCU.
8
Rev. 1.0
Si3484
3. Serial Packet Protocol
The Si3484 contains the Power Manager component and the interface to the Power Manager is a collection of
routines known as the Power Manager application programming interface (API).
The Power Manager API is described later in this manual. The host MCU should contain a Serial Packet Client,
which calls the routines in the Power Manager API to get status information and configure and control the Power
Manager.
The Serial packet protocol (SPP) is a remote procedure call (RPC) mechanism that allows a Serial Packet client to
call routines in the Power Manager. The Serial Packet Protocol is implemented by a Serial Packet Client in the host
MCU and the Serial Packet Server in the Si3484. The Serial Packet Client should be implemented by the user in
the host MCU. Silicon Labs has reference code available; please contact Silicon Labs for further information.
The Serial Packet Server receives a packet from a Serial Packet Client and then calls the specified routine in the
Power Manager. When the Power Manager routine returns, the Serial Packet Server sends a packet back to the
Serial Packet Client.
Host MCU
Host Controller Firmware
Serial Packet Client
Replies
Serial Packet Protocol
Queries
UART or SPI
(Remote Procedure Call)
Si3484
Serial Packet Server
Power Manager
PSE Controller Support
I2C
Si3459 or Si3454
Figure 6. Serial Packet Protocol
Rev. 1.0
9
Si3484
3.1. Packet Format
A packet is a sequence of fields sent together as a unit. Figure 7 shows the SPP packet format.
Start Routine Data Length Data Checksum
Figure 7. Packet Format
Each field is a single byte except for the Data field. The Data field length may be from zero to 255 bytes.
3.1.1. Start Field
The Start field marks the beginning of a packet and always contains the Start-of-Packet (SOP) character (0xAC). If
data is lost on the host interface, the Serial Packet Server and the Serial Packet Client use the Start field to
resynchronize. A “receive packet” routine starts by receiving and discarding bytes until the SOP character is found.
3.1.2. Checksum Field
The Checksum field is used to verify that the packet was not corrupted during transmission. The sender of a packet
calculates the checksum and writes it into the Checksum field. The receiver of a packet verifies that the checksum
is correct. The Checksum field should contain the value such that all the bytes in the packet, except for the Start
field, add up to zero.
Start Routine Data Length Data Checksum
Sum of Bytes is Zero
Figure 8. Packet Checksum
To calculate the checksum, the sender uses an 8-bit variable to sum up the bytes of the Routine field through the
end of the Data field. The sender adds one to the one's complement of this sum and stores the result in the
Checksum field.
Checksum = ~Sum + 1
To verify the checksum, the receiver uses an 8-bit variable to sum up the bytes of the Routine field through the
Checksum field. The sum should be zero.
3.1.3. Routine Field
The Routine field identifies a routine in the Power Manager API.
The client uses the Routine field to specify which routine to call. The client should verify that the Routine field in a
received packet matches the Routine field in the sent packet. Definitions of routines can be found in “4. Power
Manager API” .
3.1.4. Data Length Field
The DataLength field specifies the number of bytes in the Data field. The number of bytes may be from zero to 255.
3.1.5. Data Field
The Data field is used to pass data to and from the Si3484. The Data field may contain four different types of data:
Parameters
System
Information
Port Information
Events
The Data field has a different format for each type of data. The format of commands issued by the host to the
power manager is fixed, but the format of the returned values may be of four different types: Parameters, System
Information, Port Information, and Events.
To elaborate, in all packets issued by the host, the Data Field has the Parameters format. Most of the returned
packet are also in the Parameters format, the only exceptions being the packets that are received back after calling
10
Rev. 1.0
Si3484
the RTN_GETSYSTEMINFO, RTN_GETPORTINFO, and RTN_GETEVENTS routines. The Data Fields for these
return packets are in the System Information format, Port Information format, and Events format, respectively.
3.1.5.1. Parameters Format
The Parameters format of the Data field is used to pass parameters to Power Manager routines. In most cases, the
Parameters format is also used to return data from the routines.
Start Routine Data Length Data Checksum
Parm8
Parm32
Figure 9. Parameters Format
The Parameters format has an 8-bit Parm8 field followed by a 32-bit Parm32 field (see Table 6). Depending on the
routine being called, Parm8, Parm32, or both fields are used. Sometimes, neither field is used. However, both
fields are always sent and received. The DataLength field contains five.
Table 6. Use of Parameters
Parameters in Query Packet
Parameters in Reply Packet
Routine
Parm8
Parm32*
Get System Status
Parm8
Parm32*
SystemStatus
Get System Info
Uses System Information Format
Get Total Power Consumed
PowerConsumed
Get Total Power Granted
PowerGranted
Get Total Power Provided
PowerProvided
Get Port Count
PortCount
Get Port Status
Port
PortStatus
Get Port Info
Port
Get Port Priority Status
Port
Get Port Power Consumed
Port
PowerConsumed
Get Port Power Granted
Port
PowerGranted
Get Port Power Requested
Port
PowerRequested
Get Port Power Available
Port
PowerAvailable
Uses Port Information Format
PortPriorityStatus
Reset System
Result
Restore Factory Defaults
Store Configuration
Set Port Control
Port
Control
Result
Adjust Port Power
Port
PortPower
Result
Set Power Provided
PowerSupply
PowerProvided
Result
*Note: The Parm32 field is big endian; therefore, the most significant byte is first.
Rev. 1.0
11
Si3484
Table 6. Use of Parameters (Continued)
Parameters in Query Packet
Parameters in Reply Packet
Routine
Parm8
Get Power Provided
PowerSupply
Set Reserved Power
ReservedPower
Parm32*
Result
ReservedPower
OverloadLimit
Result
Get Overload Limit
Set Granting Policy
OverloadLimit
GrantingPolicy
Result
Get Granting Policy
Set Retry Policy
GrantingPolicy
RetryPolicy
Result
Get Retry Policy
RetryPolicy
Set Port Enable
Port
Get Port Enable
Port
Set Port Capability
Port
Get Port Capability
Port
Set Port Midspan
Port
Get Port Midspan
Port
Set Port Priority
Port
Get Port Priority
Port
Set Port Legacy Support
Port
Get Port Legacy Support
Port
Set Port Power Limit
Port
Get Port Power Limit
Port
Get Power Supply Status
PowerSupply
Enable
Result
Enable
Capability
Result
Capability
Location
Result
Location
Priority
Result
Priority
Legacy
Result
Legacy
PowerLimit
Result
PowerLimit
Status
Get Events
Uses Events Format
Get System Time
Set Power Inflation
System Time in ms
Power Inflation
Get Power Inflation
Set Soft Start Policy
Power Inflation
Soft Start Policy
Get Soft Start Policy
Soft Start Policy
*Note: The Parm32 field is big endian; therefore, the most significant byte is first.
12
Parm32*
PowerProvided
Get Reserved Power
Set Overload Limit
Parm8
Rev. 1.0
Si3484
3.1.5.2. System Information Format
The System Information format of the Data field is used to return system information to the client. System
information is returned after calling the RTN_GETSYSTEMINFO routine.
Start Routine Data Length Data Checksum
PowerManagerVersion PlatformSupportVersion
Figure 10. System Information Format
The System Information format has a PowerManagerVersion field followed by a PlatformSupportVersion field. Both
of these fields are eight bytes long and contain a version string that is a zero-terminated ASCII string. A version
string may be from one to seven characters long. The Routine field contains RTN_GETSYSTEMINFO, and the
DataLength field contains 16.
3.1.5.3. Port Information Format
The Port Information format of the Data field is used to return port information to the client. Port information is
returned after calling the RTN_GETPORTINFO routine.
Start Routine Data Length Data Checksum
Result Detection Classification Current
Power Supply Silicon Firmware
Voltage
Version Version
Figure 11. Port Information Format
The Port Information format is a sequence of fields as shown above. For more information, read the description of
the RTN_GETPORTINFO routine in the Power Manager API Section. The Routine field contains
RTN_GETPORTINFO, and the DataLength field contains 17.
The Result field contains the return code from the RTN_GETPORTINFO routine, and, if Result is not SUCCESS
(0), the remaining fields should be ignored.
The Current and PowerSupplyVoltage fields are big endian. Therefore, the most significant byte comes first.
3.1.5.4. Events Format
The Events format of the Data field is used to return events to the client. Events are returned after calling the
RTN_GETEVENTS routine.
Start Routine Data Length Data Checksum
Event
Type
Event
Parm1
Event
...
Event
Parm2
Figure 12. Events Format
In the Si3484, the Serial Packet Server internally receives events from the Power Manager and stores them in a
circular event queue. If the event queue becomes full, newer events overwrite older events.
If a client wishes to receive events, it should periodically get the events from the Serial Packet Server. The client
gets the events by sending a packet with the Routine field set to RTN_GETEVENTS. The Serial Packet Server
returns all the events from the event queue in a single packet with the Data field in the Events format.
Rev. 1.0
13
Si3484
The Data field does not have a fixed length. The length of the Data field depends on the number of events that are
returned. An event is three bytes long; so, the number of events in the Data field is DataLength divided by three. If
there are no events to return, then DataLength is zero, and the Data field is empty. The maximum number of events
that can be returned is 72.
3.1.6. Serial Packet Formats
All four packet formats must use the same “Parameters” packet format when the host issue a transfer even if the
return format is System Info, Port Info or Event.
3.2. SPP Error Handling
There are many reasons why a client may not receive back a packet. Perhaps the Si3484 is not running or perhaps
the serial data was corrupted or lost during transmission (in either direction). In any case, it is not prudent for a
Serial Packet Client to call a serial receive routine that blocks forever until data is received. If the serial receive
routine does not have a timeout option, the client should not call the receive routine unless it knows that received
data is available. If a client does not receive a packet within one second of sending a packet, then the client should
assume that there has been a communications error. The client should resend the original packet or simply give up
(but do not wait forever to receive a packet).
When the Serial Packet Server receives a packet, it validates the packet. If the checksum is bad or the Routine
field is invalid, the Serial Packet Server ignores the packet and does not send back a packet in response. After one
second, the client should realize that a packet has not been received and should resend the original packet.
The Si3484 checks the configuration every 30 seconds to see if it has changed. If the configuration has changed,
the Si3484 backs up the configuration to internal flash memory. While the Si3484 is writing to flash memory, it
cannot send or receive packets on the host interface. If a host MCU sends a packet to the Si3484 while it is backing
up the configuration, the packet is lost. If a host MCU does not receive a packet back within one second, the host
MCU should resend the original packet.
14
Rev. 1.0
Si3484
4. Power Manager API
User Interface components call the routines in the Power Manager API to get status information and configure and
control the Power Manager. The Power Manager API has routines for:
Management
System
Status
Port Status
System Control
Port Control
System Configuration
Port Configuration
Power Supply Status
Events
Output packet format is ‘Parameters Format’ in all cases. Input packet format depends on the routine.
Maximum of the ‘Port’ parameter of the routines (where applicable) is 64 ports, but only ports available in the
system give a valid result.
Some functions can emit error codes. Descriptions of the error codes can be found in "4.9. Return Codes" on page
44
Values in the “Symbol” column of the tables are recommended names for constant values.
To build a valid query packet, the user must specify the routine and provide the necessary parameters. If the
parameter is indicated as “None”, the serial packet server does not rely on the passed value, so the recommended
value is 0. In case of receiving reply packets, the parameters indicated as “None” should be ignored by the host.
The serial packet server will echo back the routine name in the reply packet, which can be used along with the
checksum value to check for consistency.
Table 7 contains routines available through the serial packet protocol.
Table 7. Power Manager Routines
Routine
Value
Symbol
Get System Status
1
RTN_GETSYSTEMSTATUS
Get System Info
2
RTN_GETSYSTEMINFO
Get Total Power Consumed
3
RTN_GETTOTALPOWERCONSUMED
Get Total Power Granted
4
RTN_GETTOTALPOWERGRANTED
Get Total Power Provided
5
RTN_GETTOTALPOWERPROVIDED
Get Port Count
6
RTN_GETPORTCOUNT
Get Port Status
7
RTN_GETPORTSTATUS
Get Port Info
8
RTN_GETPORTINFO
Get Port Priority Status
9
RTN_GETPORTPRIORITYSTATUS
Get Port Power Consumed
10
RTN_GETPORTPOWERCONSUMED
Get Port Power Granted
11
RTN_GETPORTPOWERGRANTED
Get Port Power Requested
12
RTN_GETPORTPOWERREQUESTED
Rev. 1.0
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Si3484
Table 7. Power Manager Routines (Continued)
16
Routine
Value
Symbol
Get Port Power Available
13
RTN_GETPORTPOWERAVAILABLE
Reset System
14
RTN_RESETSYSTEM
Restore Factory Defaults
15
RTN_RESTOREFACTORYDEFAULTS
Set Port Control
16
RTN_SETPORTCONTROL
Adjust Port Power
17
RTN_ADJUSTPORTPOWER
Set Power Provided
18
RTN_SETPOWERPROVIDED
Get Power Provided
19
RTN_GETPOWERPROVIDED
Set Reserved Power
20
RTN_SETRESERVEDPOWER
Get Reserved Power
21
RTN_GETRESERVEDPOWER
Set Overload Limit
22
RTN_SETOVERLOADLIMIT
Get Overload Limit
23
RTN_GETOVERLOADLIMIT
Set Granting Policy
24
RTN_SETGRANTINGPOLICY
Get Granting Policy
25
RTN_GETGRANTINGPOLICY
Set Retry Policy
26
RTN_SETRETRYPOLICY
Get Retry Policy
27
RTN_GETRETRYPOLICY
Set Port Enable
28
RTN_SETPORTENABLE
Get Port Enable
29
RTN_GETPORTENABLE
Set Port Capability
30
RTN_SETPORTCAPABILITY
Get Port Capability
31
RTN_GETPORTCAPABILITY
Set Port Midspan
32
RTN_SETPORTMIDSPAN
Get Port Midspan
33
RTN_GETPORTMIDSPAN
Set Port Priority
34
RTN_SETPORTPRIORITY
Get Port Priority
35
RTN_GETPORTPRIORITY
Set Port Legacy Support
36
RTN_SETPORTLEGACYSUPPORT
Get Port Legacy Support
37
RTN_GETPORTLEGACYSUPPORT
Set Port Power Limit
38
RTN_SETPORTPOWERLIMIT
Get Port Power Limit
39
RTN_GETPORTPOWERLIMIT
Set Power Supply Status
40
RTN_SETPOWERSUPPLYSTATUS
Get Power Supply Status
41
RTN_GETPOWERSUPPLYSTATUS
Rev. 1.0
Si3484
Table 7. Power Manager Routines (Continued)
Routine
Value
Symbol
Get Events
42
RTN_GETEVENTS
Store Configuration
43
RTN_STORECONFIG
Set Soft Start Policy
45
RTN_SETSOFTSTARTPOLICY
Get Soft Start Policy
46
RTN_GETSOFTSTARTPOLICY
Get System Time
47
RTN_GETSYSTEMTIME
Set Power Inflation
48
RTN_SETPOWERINFLATION
Get Power Inflation
49
RTN_GETPOWERINFLATION
Rev. 1.0
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Si3484
4.1. System Status
The System Status routines allow a User Interface component to get the following information:
System
Status
System Info
Total Power Consumed
Total Power Granted
Total Power Provided
4.1.1. Get System Status
Get the status of the system.
Routine:
RTN_GETSYSTEMSTATUS
Query data:
Parm8:
None
Parm32:
None
Reply packet format:
Parameters
Reply data:
Parm8:
System status
Parm32:
None
The system status is the overall status of the system. A negative system status value is an error that is not specific
to a particular port.
Table 8. System Status Values
18
Status
Value
Symbol
OK
0
STATUS_SYSTEM_OK
Initialization Failed
–1
STATUS_SYSTEM_INIT_FAIL
Under Voltage
–2
STATUS_SYSTEM_UNDER_VOLT
Over Temperature
–3
STATUS_SYSTEM_OVER_TEMP
Communications Lost
–4
STATUS_SYSTEM_COMM_LOST
Rev. 1.0
Si3484
4.1.2. Get System Info
Get information about the system.
Routine:
RTN_GETSYSTEMINFO
Query data:
Parm8:
None
Parm32:
None
Reply packet format:
System Information
Reply data:
Bytes 0..7
Power Manager Version (zero-terminated string)
Bytes 8..15
Platform Support Version (zero-terminated string)
Return strings contain the version of the Power Manager and the version of the Platform Support component as
zero-terminated strings.
4.1.3. Get Total Power Consumed
Get the power consumed by all PDs.
Routine:
RTN_GETTOTALPOWERCONSUMED
Query data:
Parm8:
None
Parm32:
None
Reply packet format:
Parameters
Reply data:
Parm8:
None
Parm32:
Total power consumed in mW
4.1.4. Get Total Power Granted
Get the power granted to all PDs.
Routine:
RTN_GETTOTALPOWERGRANTED
Query data:
Parm8:
None
Parm32:
None
Reply packet format:
Parameters
Reply data:
Parm8:
None
Parm32:
Total power granted in mW
Rev. 1.0
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Si3484
4.1.5. Get Total Power Provided
Get the power provided by all power supplies
Routine:
RTN_GETTOTALPOWERPROVIDED
Query data:
Parm8:
None
Parm32:
None
Reply packet format:
Parameters
Reply data:
20
Parm8:
None
Parm32:
Total power provided in mW
Rev. 1.0
Si3484
4.2. Port Status
The Port Status routines allow a User Interface component to get the following information:
Port
Count
Port Status
Port Info
Port Priority Status
Port Power Consumed
Port Power Granted
Port Power Requested
Port Power Available
4.2.1. Get Port Count
Get the number of ports in the system.
Routine:
RTN_GETPORTCOUNT
Query data:
Parm8:
None
Parm32:
None
Reply packet format:
Parameters
Reply data:
Parm8:
Number of ports in the system
Parm32:
None
When the Power Manager starts up, it discovers the number of ports in the system by searching for port controllers.
4.2.2. Get Port Status
Get the status of a port.
Routine:
RTN_GETPORTSTATUS
Query data:
Parm8:
Port number
Parm32:
None
Reply packet format:
Parameters
Reply data:
Parm8:
Port status value or an error code
Parm32:
None
Rev. 1.0
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Si3484
Table 9. Port Status Values
Status
Value
Symbol
Description
Disabled
0
STATUS_PORT_DISABLED
The port is off because it is not allowed to turn
on.
Powered On
1
STATUS_PORT_POWERED_ON A PD is connected and receiving power.
Powered Off
2
STATUS_PORT_POWERED_OFF The port is off because a PD is not connected.
Denied
3
STATUS_PORT_DENIED
Blocked
4
STATUS_PORT_BLOCKED
Forced On
5
STATUS_PORT_FORCED_ON
The user forced the port on.
Forced Off
6
STATUS_PORT_FORCED_OFF
The user forced the port off.
The port is off because there is not enough
power remaining to grant the power request.
The port is off because of a port overload.
If a port is blocked, then the PD consumed more power than it was granted (port overload), and the retry policy is
“retry after reconnect”. To remove the block, the user must physically disconnect the PD from the port. Another way
to remove the block is to disable and then re-enable the port.
4.2.3. Get Port Info
Get low-level port information.
Routine:
RTN_GETPORTINFO
Query data:
Parm8:
Port number
Parm32:
None
Reply packet format:
Port Information
Reply data:
22
Byte 0:
Result
Byte 1:
Detection value (see table 11.)
Byte 2:
Classification value (see table 12.)
Byte 3..4:
Port current in mA, 16bit, MSB first
Byte 5..6:
Power supply voltage in mV, 16bit, MSB first
Byte 7..8:
PSE silicon version
Byte 9..14:
PSE firmware version
Rev. 1.0
Si3484
Table 10. Detect Values
Detection Result
Value
Symbol
Unknown
0
DETECT_UNKNOWN
Short
1
DETECT_SHORT
Low
3
DETECT_LOW
Good
4
DETECT_GOOD
High
5
DETECT_HIGH
Open
6
DETECT_OPEN
Table 11. Classification Values
Classification Result
Value
Symbol
Unknown
0
CLASS_UNKNOWN
Class 1
1
CLASS_1
Class 2
2
CLASS_2
Class 3
3
CLASS_3
Class 4
4
CLASS_4
Unequal fingers
5
CLASS_UNEQ_FINGERS
Class 0
6
CLASS_0
Overload
7
CLASS_OVERLOAD
4.2.4. Get Port Priority Status
Get the priority status of a port.
Routine:
RTN_GETPORTPRIORITYSTATUS
Query data:
Parm8:
Port number
Parm32:
None
Reply packet format:
Parameters
Reply data:
Parm8:
Port priority status
Parm32:
None
Rev. 1.0
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Si3484
Table 12. Port Priority Status Values
Status
Value
Symbol
Low
0
PRIORITY_LOW
High
1
PROIRITY_HIGH
Forced
2
PRIORITY_FORCED
Critical
3
PRIORITY_CRITICAL
The priority status of a port is the currently-active priority and may be different than the configured priority of the
port. If a port is forced on or off and the configured priority is low or high, the priority status is elevated to the forced
priority. If a forced port is returned to automatic control, the Power Manager returns the priority status to the
configured priority.
4.2.5. Get Port Power Consumed
Get the power that a PD is currently using.
Routine:
RTN_GETPORTPOWERCONSUMED
Query data:
Parm8:
Port
Parm32:
None
Reply packet format:
Parameters
Reply data:
Parm8:
None
Parm32:
Port power consumed in mW or an error code
4.2.6. Get Port Power Granted
Get the power that is allocated to a PD.
Routine:
RTN_GETPORTPOWERGRANTED
Query data:
Parm8:
Port
Parm32:
None
Reply packet format:
Parameters
Reply data:
24
Parm8:
None
Parm32:
Port power granted in mW or an error code
Rev. 1.0
Si3484
4.2.7. Get Port Power Requested
Get the power that is requested by a PD.
Routine:
RTN_GETPORTPOWERREQUESTED
Query data:
Parm8:
Port
Parm32:
None
Reply packet format:
Parameters
Reply data:
Parm8:
None
Parm32:
Port power requested in mW or an error code
4.2.8. Get Port Power Available
Get the power that is available for a PD.
Routine:
RTN_GETPORTPOWERAVAILABLE
Query data:
Parm8:
Port
Parm32:
None
Reply packet format:
Parameters
Reply data:
Parm8:
None
Parm32:
Port power available in mW or an error code
An LLDP agent calls this routine to determine maximum power that the power manager can provide for a port. If a
port has a power limit, then the power limit is returned. If a port does not have a power limit and the port can supply
high power, then 40 W (maximum power) is returned; otherwise, 15.4 W (low power) is returned.
Rev. 1.0
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Si3484
4.3. System Control
The System Control routines allow a User Interface component to:
Reset
the system
factory default settings
Store the configuration immediately in the non-volatile memory
Retrieve the system’s internal time
Restore
4.3.1. Reset System
Reset the system.
Routine:
RTN_RESETSYSTEM
Query data:
Parm8:
None
Parm32:
None
Reply packet format:
Parameters
Reply data:
Parm8:
Result. Zero (for success) or an error code
Parm32:
None
4.3.2. Restore Factory Default
Restore the configuration to factory default values.
Routine:
RTN_RESTOREFACTORYDEFAULTS
Query data:
Parm8:
None
Parm32:
None
Reply packet format:
Parameters
Reply data:
26
Parm8:
None
Parm32:
None
Rev. 1.0
Si3484
4.3.3. Store Configuration
Store the configuration immediately in the non-volatile memory.
Routine:
RTN_STORECONFIG
Query data:
Parm8:
None
Parm32:
None
Reply packet format:
Parameters
Reply data:
Parm8:
None
Parm32:None
4.3.4. Get System Time
Return the system time in milliseconds since system restart.
Routine:
RTN_GETSYSTEMTIME
Query data:
Parm8:
None
Parm32:
None
Reply packet format:
Parameters
Reply data:
Parm8:
None
Parm32:
The time in milliseconds since system restart.
Rev. 1.0
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Si3484
4.4. Port Control
The Port Control routines allow a User Interface component to:
Set port control
Adjust port power
4.4.1. Set Port Control
Controls the method of port turn on and off
Routine:
RTN_SETPORTCONTROL
Query data:
Parm8:
Port number
Parm32:
Control
Reply packet format:
Parameters
Reply data:
Parm8:
Zero (for success) or an error code
Parm32:
None
Table 13. Control Values
Control
Value
Symbol
Automatic
0
PORT_CTRL_AUTOMATIC
Force on
1
PORT_CTRL_FORCE_ON
Force off
2
PORT_CTRL_FORCE_OFF
If the port control is automatic, the Power Manager automatically turns the port on and off when a PD is connected
and disconnected from the port. If the port control is forced on, the port's priority is boosted to the forced priority
level. This usually results in the port turning on. However, a forced port cannot cause a critical priority port to turn
off in order to turn on the forced port. If a forced port is granted power, the Power Manager turns on a forced port
even if no PD is detected. If the port control is forced off, the port is unconditionally turned off and held off. A forcedoff port is considered to be temporarily off, while a disabled port is considered to be permanently off.
4.4.2.AdjustPortPower
Adjust the power granted to a PD.
Routine:
RTN_ADJUSTPORTPOWER
Query data:
Parm8:
Port
Parm32:
Requested port power in mW
Reply packet format:
Parameters
Reply data:
28
Parm8:
Zero (for success) or an error code
Parm32:
None
Rev. 1.0
Si3484
An LLDP agent calls this routine to reallocate the power granted to a PD. The agent can request more power than
is currently granted or it can request less power than is currently granted. This routine allows an LLDP agent to
dynamically change the amount of power granted to a PD during the course of a connection. A port must be on
before its power can be adjusted.
Rev. 1.0
29
Si3484
4.5. System Configuration
The System Configuration routines allow a User Interface component to set and get these items:
Power
provided
Reserved power
Overload limit
Granting policy
Retry policy
Power inflation
Soft start policy
4.5.1. Set Power Provided
Set the amount of power that is output from a power supply.
Routine:
RTN_SETPOWERPROVIDED
Query data:
Parm8:
Power supply (1 to 3)
Parm32:
Power provided by the power supply in mW
Reply packet format:
Parameters
Reply data:
Parm8:
Zero (for success) or an error code
Parm32:
None
4.5.2. Get Power Provided
Get the amount of power that is output from a power supply.
Routine:
RTN_ RTN_GETPOWERPROVIDED
Query data:
Parm8:
Power supply (1 to 3)
Parm32:
None
Reply packet format:
Parameters
Reply data:
30
Parm8:
None
Parm32:
Power provided by the power supply in mW
Rev. 1.0
Si3484
4.5.3. Set Reserved Power
Set the percentage of power that is reserved from granting.
Routine:
RTN_SETRESERVERPOWER
Query data:
Parm8:
Reserved power in percentage of the total power
provided
Parm32:
None
Reply packet format:
Parameters
Reply data:
Parm8:
Zero (for success) or an error code
Parm32:
None
4.5.4. Get Reserved Power
Get the percentage of power that is reserved from granting.
Routine:
RTN_GETRESERVEDPOWER
Query data:
Parm8:
None
Parm32:
None
Reply packet format:
Parameters
Reply data:
Parm8:
Reserved power in percentage of the total power
provided
Parm32:
None
If the granting policy is consumption-based, the Power Manager holds this amount of power in reserve. The Power
Manager does not use the reserved power to grant new requests. This creates a power buffer that reduces the
likelihood of system overloads caused by momentary surges in consumption.
4.5.5. Set Overload Limit
Set the maximum system overload that the power supplies can tolerate.
Routine:
RTN_SETOVERLOADLIMIT
Query data:
Parm8:
Overload limit as a percentage of the total power
provided
Parm32:
None
Reply packet format:
Parameters
Reply data:
Parm8:
Zero (for success) or an error code
Parm32:
None
Rev. 1.0
31
Si3484
4.5.6. Get Overload Limit
Get the maximum system overload that the power supplies can tolerate.
Routine:
RTN_GETOVERLOADLIMIT
Query data:
Parm8:
None
Parm32:
None
Reply packet format:
Parameters
Reply data:
Parm8:
Overload limit as a percentage of the total power
provided
Parm32:
None
The overload limit is the maximum system overload that the power supplies can tolerate. It is expressed as a
percentage of the total power provided. If a system overload is less than the overload limit, the ports are turned off
one at a time. If a system overload is greater than the overload limit (severe overload), all of the low-priority ports
are immediately turned off.
4.5.7. Set Granting Policy
Set the granting policy.
Routine:
RTN_SETGRANTINGPOLICY
Query data:
Parm8:
Granting policy
Parm32:
None
Reply packet format:
Parameters
Reply data:
Parm8:
Zero (for success) or an error code
Parm32:
None
4.5.8. Get Granting Policy
Get the granting policy.
Routine:
RTN_GETGRANTINGPOLICY
Query data:
Parm8:
None
Parm32:
None
Reply packet format:
Parameters
Reply data:
32
Parm8:
Granting policy
Parm32:
None
Rev. 1.0
Si3484
Table 14. Granting Policy Values
Granting Policy
Value
Symbol
Grant-based
0
GRANT_POLICY_GRANT_BASED
Consumption-based
1
GRANT_POLICY_CONSUMPTION_BASED
The granting policy is used by the Power Manager when deciding if a request for power should be granted. If the
granting policy is grant based, the remaining power is considered to be the total ungranted power. If the granting
policy is consumption-based, the remaining power is considered to be the total unconsumed power (excluding the
reserved power). If the remaining power is greater than or equal to the requested power, then the Power Manager
grants the request.
Grantbased:
PowerRemaining = TotalPowerProvided–TotalPowerGranted
Consumptionbased:
PowerRemaining = TotalPowerProvided–TotalPowerConsumed–ReservedPower
4.5.9. Set Retry Policy
Set the retry policy.
Routine:
RTN_SETRETRYPOLICY
Query data:
Parm8:
Retry policy
Parm32:
None
Reply packet format:
Parameters
Reply data:
Parm8:
Zero (for success) or an error code
Parm32:
None
4.5.10. Get Retry Policy
Get the retry policy.
Routine:
RTN_GETRETRYPOLICY
Query data:
Parm8:
None
Parm32:
None
Reply packet format:
Parameters
Reply data:
Parm8:
Retry policy
Parm32:
None
Rev. 1.0
33
Si3484
Table 15. Retry Policy Values
Retry Policy
Value
Symbol
Immediate
0
RETRY_IMMEDIATELY
Reconnect
1
RETRY_AFTER_RECONNECT
Re-enable
2
RETRY_AFTER_REENABLE
The retry policy specifies when the Power Manager tries again to power a port that is turned off because of a port
overload. A port overload is when the power consumed by a PD is greater than the power granted to that PD. If the
retry policy is “immediate”, the Power Manager tries to turn the port back on immediately. If the retry policy is
“reconnect”, the Power Manager waits until the PD is disconnected and then reconnected before it tries again to
power the port. The Power Manager must detect an open circuit on the port before retrying. If the retry policy is “reenable”, the Power Manager disables the port when a port overload occurs. The user must re-enable the port
before the Power Manager tries to power the port again.
4.5.11. Set Power Inflation
Set the power inflation applied to all ports.
Routine:
RTN_SETPOWERINFLATION
Query data:
Parm8:
The power inflation as a percentage of a port’s granted power
Parm32:
None
Reply packet format:
Parameters
Reply data:
Parm8:
Zero (for success) or an error code
Parm32:
None
4.5.12. Get Power Inflation
Get the power inflation applied to all ports
Routine:
RTN_GETPOWERINFLATION
Query data:
Parm8:
None
Parm32:
None
Reply packet format:
Parameters
Reply data:
Parm8:
The power inflation as a percentage of a port’s granted power
Parm32:
None
Power inflation allows a port to draw a fixed percentage more than its granted power. It is a global setting applied to
each port independently. It is a configuration parameter bound between 0% and 25% of granted power.
34
Rev. 1.0
Si3484
4.5.13. Set Soft Start Policy
Set the Soft Start Policy for the system
Routine:
RTN_SETSOFTSTARTPOLICY
Query data:
Parm8:
Soft start policy
Parm32:
None
Reply packet format:
Parameters
Reply data:
Parm8:
Zero (for success) or an error code
Parm32:
None
4.5.14. Get Soft Start Policy
Get the power inflation applied to all ports
Routine:
RTN_GETSOFTSTARTPOLICY
Query data:
Parm8:
None
Parm32:
None
Reply packet format:
Parameters
Reply data:
Parm8:
Soft start policy
Parm32:
None
Soft start boots the system with 0W total power to avoid unintentional port turn on in a host-controlled environment.
After system boot using soft start, the host should call “Set Power Provided” to provide the actual supply wattage to
the system.
Table 16. Soft Start Policy Values
Soft Start Policy
Value
Symbol
Soft start disabled
0
SOFT_START_DISABLED
Soft start enabled
1
SOFT_START_ENABLED
Rev. 1.0
35
Si3484
4.6. Port Configuration
The Port Configuration routines allow a User Interface component to set and get
Port
enable
Port capability
Port priority
Port power limit
Power location
4.6.1. Set Port Enable
Set whether a port is enabled to turn on.
Routine:
RTN_SETPORTENABLE
Query data:
Parm8:
Port
Parm32:
Enable (enable: 1, disable: 0)
Reply packet format:
Parameters
Reply data:
Parm8:
Zero (for success) or an error code
Parm32:
None
4.6.2. Get Port Enable
Get whether a port is allowed to turn on.
Routine:
RTN_GETPORTENABLE
Query data:
Parm8:
Port
Parm32:
None
Reply packet format:
Parameters
Reply data:
36
Parm8:
Enable (enabled: 1, disabled: 0) or error code
Parm32:
None
Rev. 1.0
Si3484
4.6.3. Set Port Capability
Set whether a port can supply high power.
Routine:
RTN_SETPORTCAPABILITY
Query data:
Parm8:
Port
Parm32:
Capability
Reply packet format:
Parameters
Reply data:
Parm8:
Zero (for success) or an error code
Parm32:
None
4.6.4. Get Port Capability
Get whether a port is allowed to turn on.
Routine:
RTN_GETPORTCAPABILITY
Query data:
Parm8:
Port
Parm32:
None
Reply packet format:
Parameters
Reply data:
Parm8:
Capability or error code
Parm32:
None
Table 17. Port Capability Values
Capability
Value
Symbol
Low power
0
CAPABILITY_LOW_POWER
High power
1
CAPABILITY_HIGH_POWER
If the port hardware is designed to supply high power (PoE+), set Capability to one. Otherwise, set Capability to
zero. Note that a port’s capability cannot be changed while the port is on
Rev. 1.0
37
Si3484
4.6.5. Set Port Power Location
Set the location of the power source.
Routine:
RTN_SETPORTPOWERLOCATION
Query data:
Parm8:
Port
Parm32:
Location
Reply packet format:
Parameters
Reply data:
Parm8:
Zero (for success) or an error code
Parm32:
None
4.6.6. Get Port Power Location
Get the location of the power source.
Routine:
RTN_GETPORTPOWERLOCATION
Query data:
Parm8:
Port
Parm32:
None
Reply packet format:
Parameters
Reply data:
Parm8:
Location or error code
Parm32:
None
Table 18. Power Location Values
Location
Value
Symbol
Endpoint
0
LOCATION_ENDPOINT
Midspan
1
LOCATION_MIDSPAN
If the power source is within an Ethernet switch, the location is “endpoint”. If the power source is inserted between
an Ethernet switch and a PD, the location is “midspan”. The Power Manager uses different back-off timings for
different locations. The Power Manager assumes that an endpoint device uses the Alternative A pinout and that a
midspan device uses the Alternative B pinout. For alternative A, power is applied to wire pairs 1,2 and 3,6. For
alternative B, power is applied to wire pairs 4,5 and 7,8
(the spare pairs in the case of 10/100 Ethernet). Conventionally, alternative B is used for midspan power injectors.
For alternative B, detection is done with over 2 seconds between detection pulses so as to avoid interfering with
end-point equipment trying to provide power using alternative A.
38
Rev. 1.0
Si3484
4.6.7. Set Port Priority
Set the priority of a port.
Routine:
RTN_SETPORTPRIORITY
Query data:
Parm8:
Port
Parm32:
Priority
Reply packet format:
Parameters
Reply data:
Parm8:
Zero (for success) or an error code
Parm32:
None
4.6.8. Get Port Priority
Get the priority of a port.
Routine:
RTN_GETPORTPRIORITY
Query data:
Parm8:
Port
Parm32:
None
Reply packet format:
Parameters
Reply data:
Parm8:
Priority or error code
Parm32:
None
Table 19. Port Priority Values
Priority
Value
Symbol
Low
0
PRIORITY_LOW
High
1
PRIORITY_HIGH
Critical
3
PRIORITY_CRITICAL
The priority of a port indicates how important it is that the port receives power. If there is not enough power
provided for all ports that want power, then the low priority ports are the first ports to be denied. Critical priority ports
are the last ports to be denied.
If a port is forced on, then the port's priority is elevated to the forced priority level. Forced priority is between high
priority and critical priority and cannot be directly set by the user. When a port is forced on, it may cause a high
priority port to be turned off, but it can never cause a critical priority port to be turned off.
If a severe overload occurs, all of the low priority ports are immediately powered off.
Rev. 1.0
39
Si3484
4.6.9. Set Port Legacy Support
Enable or disable legacy support.
Routine:
RTN_SETPORTLEGACYSUPPORT
Query data:
Parm8:
Port
Parm32:
Enable (enable: 1, disable: 0)
Reply packet format:
Parameters
Reply data:
Parm8:
Zero (for success) or an error code
Parm32:
None
If disabled then only IEEE standard 802.3AF- or AT-compatible PDs will be detected. Otherwise non-standard PDs
with large common-mode capacitance (legacy PDs) will be detected as well.
4.6.10. Get Port Legacy Support
Get the legacy support setting of a port
Routine:
RTN_GETPORTLEGACYSUPPORT
Query data:
Parm8:
Port
Parm32:
None
Reply packet format:
Parameters
Reply data:
Parm8:
Enable (enable: 1, disable: 0) or error code
Parm32:
None
If enabled the legacy PDs will be detected.
4.6.11. Set Port Power Limit
Set the power limit of a port.
Routine:
RTN_SETPORTPOWERLIMIT
Query data:
Parm8:
Port
Parm32:
Limit, maximum power that may be granted to a port
in mW
Reply packet format:
Parameters
Reply data:
40
Parm8:
Zero (for success) or an error code
Parm32:
None
Rev. 1.0
Si3484
4.6.12. Get Port Power Limit
Get the power limit of a port
Routine:
RTN_GETPORTPOWERLIMIT
Query data:
Parm8:
Port
Parm32:
None
Reply packet format:
Parameters
Reply data:
Parm8:
None
Parm32:
Limit, maximum power that may be granted to a port
in mW
Power limit restricts the amount of power that may be granted to a port. If a port's power limit is zero, the Power
Manager grants the power requested without restriction. If a port's power limit is greater than zero, the Power
Manager grants the lesser of the power limit or the power requested. If a power request is greater than the power
limit, the Power Manager grants less power than requested.
Rev. 1.0
41
Si3484
4.7. Power Supply Status
The Power Supply Status routine allows a User Interface component to get:
Power Supply Status
4.7.1. Get Power Supply Status
Get the status of a power supply.
Routine:
RTN_GETPOWERSUPPLYSTATUS
Query data:
Parm8:
Port
Parm32:
None
Reply packet format:
Parameters
Reply data:
Parm8:
Status
Parm32:
None
Table 20. Power Supply Status Values
Status
Value
Symbol
Removed
0
STATUS_POWER_SUPPLY_REMOVED
Inserted
1
STATUS_POWER_SUPPLY_INSERTED
A User Interface component calls this function to determine whether a power supply is present in a bay.
If the voltage on the specified power supply pin (PS1, PS2, or PS3) is high, this routine returns
STATUS_POWER_SUPPLY_INSERTED, otherwise, this routine returns STATUS_POWER_SUPPLY_REMOVED.
42
Rev. 1.0
Si3484
4.8. Events
The Event routine allows a User Interface component to get:
System
events
Port events
Power supply events
Error events
Informational events
4.8.1. Get Events
Get the events from the event queue.
Routine:
RTN_GETEVENTS
Query data:
Parm8:
None
Parm32:
None
Reply packet format:
Events
Reply data:
This routine returns a series of event descriptors (maximum 72) which consist of 3 bytes each:
Byte 0:
Event type
Byte 1:
Parm1, value depends on event type
Byte 2:
Parm2, optional, value depends on event type
Table 21. Event Type Values
Event Type
Value
Symbol
System
1
EVENT_TYPE_SYTSEM
Port
2
EVENT_TYPE_PORT
Power supply
4
EVENT_TYPE_POWER_SUPPLY
Error
8
EVENT_TYPE_ERROR
Information
16
EVENT_TYPE_INFO
Parameters Parm1 and Parm2 depend on event type:
System
event:
zParm1:
zParm2:
Port
value corresponding to System status values (see Table 9.)
None
event:
zParm1:
zParm2:
Power
supply event:
zParm1:
zParm2:
Error
value corresponding to Port status values (see Table 10.)
port number
value corresponding to Power supply status values (see Table 20.)
power supply number
event:
zParm1:
zParm2:
value corresponding to System status values (see Table 23.)
error specific
Rev. 1.0
43
Si3484
Informational
event:
zParm1:
value corresponding to System status values (see Table 22.)
zParm2: None
Table 22. Information Code Values
Event Type
Value
Symbol
Restored to factory defaults
1
INFO_DEFAULTS_RESTORED
System reset
2
INFO_SYSTEM_RESET
Configuration saved
3
INFO_CONFIG_SAVED
4.9. Return Codes
The routines of the Power Manager API return codes to indicate the success or failure of an operation. These
codes are also used in Parm1 of error events and information events.
Table 23. Return Code Values
44
Return Code
Value
Symbol
Success
0
SUCCESS
Port number is invalid
–1
ERROR_PORT_INVALID
Power supply number is invalid
–2
ERROR_PWR_SUPLY_INVALID
Parameter is invalid
–3
ERROR_PARAMETER_INVALID
Cannot create resource
–4
ERROR_RESOURCE_CREATE
Resource is invalid
–5
ERROR_RESOURCE_INVALID
Cannot configure resource
–6
ERROR_RESOURCE_CONFIG
Cannot read from resource
–7
ERROR_RESOURCE_READ
Cannot write to resource
–8
ERROR_RESOURCE_WRITE
Cannot find the resource
–9
ERROR_RESOURCE_NOT_FND
Cannot load the configuration
–10
ERROR_CONFIG_LOAD
Cannot save the configuration
–11
ERROR_CONFIG_SAVE
Configuration data is invalid
–12
ERROR_CONFIG_INVALID
Configuration data is corrupt
–13
ERROR_CONFIG_CORRUPT
System overload
–14
ERROR_SYSTEM_OVERLOAD
Port overload
–15
ERROR_PORT_OVERLOAD
Startup overload
–16
ERROR_STARTUP_OVERLOAD
Rev. 1.0
Si3484
MOSI
NSS
TX
RX
RSVD
INT
5. Pin Descriptions
24
23
22
21
20
19
MISO
1
18 SDA
SCK
2
17 SCL
GND
3
Top View
(Pads on Bottom of Package )
16 BAUD0
6
13 PSLCT
7
8
9
10
11
12
PS1
RSVD
PS2
14
PS3
5
RSVD
RST
RSVD
4
RESET_PSE
VDD
15 BAUD1
RSVD
Table 24. Si3484 Pin Descriptions
Pin #
Name
Type
Description
1
MISO
Output
SPI output.
2
SCK
Input
SPI clock.
3
GND
Power
Ground.
4
VDD
Power
VDD.
5
RST
Input
6
RSVD
Reserved
7
RESET_PSE
Output
8
RSVD
Reserved
Do not connect.
9
RSVD
Reserved
Do not connect.
10
PS3
Input
Logic high indicates the power supply is available.
11
PS2
Input
Logic high indicates the power supply is available.
12
PS1
Input
Logic high indicates the power supply is available.
13
PSLCT
Input
Tie low to select SPI interface. Tie high to select UART interface.
14
RSVD
Reserved
15
BAUD1
Input
Reset (a low will reset the Si3484).
Do not connect.
Reset output for connection to reset input pins of Si3459 or Si3454
PSE controllers.
Do not connect.
Tie high or low to select UART baud rate.
Rev. 1.0
45
Si3484
Table 24. Si3484 Pin Descriptions (Continued)
46
Pin #
Name
Type
Description
16
BAUD0
Input
17
SCL
Open Collector Connect to Si3459 SCL and pull up resistor.
18
SDA
Open Collector Connect to Si3459 SDA and pull up resistor.
19
INT
Input
20
RSVD
Reserved
Do not connect.
21
RX
Input
UART receive.
22
TX
Output
UART transmit.
23
NSS
Input
SPI select.
24
MOSI
Input
SPI input.
Tie high or low to select UART baud rate.
Connect to Si3459 INT and pull up resistor.
Rev. 1.0
Si3484
6. Ordering Guide
Table 25. Si3484 Ordering Guide
Ordering Part Number
Description
Package Information
Si3484-A01-GM
Power management controller
24-pin 4x4 mm QFN
RoHS compliant
Notes:
1. Add “R” to the part number to denote tape and reel option (Si3484-A01-GMR).
2. The ordering part number is not the same as the device mark. See "7. Package Outline: 24-Pin QFN" on page 48 for
device marking information.
Rev. 1.0
47
Si3484
7. Package Outline: 24-Pin QFN
The Si3484 is packaged in an industry-standard, RoHS-compliant 4x4 mm2, 24-pin QFN package.
Figure 13. 24-Pin QFN Mechanical Diagram
48
Rev. 1.0
Si3484
Table 26. QFN-24 Package Dimensions
Dimension
Min
Nom
Max
A
0.70
0.75
0.80
A1
0.00
0.02
0.05
b
0.18
0.25
0.30
D
D2
4.00 BSC
2.55
2.70
e
0.50 BSC
E
4.00 BSC
2.80
E2
2.55
2.70
2.80
L
0.30
0.40
0.50
L1
0.00
—
0.15
aaa
—
—
0.15
bbb
—
—
0.10
ddd
—
—
0.05
eee
—
—
0.08
Z
—
0.24
—
Y
—
0.18
—
Notes:
1. All dimensions shown are in millimeters (mm) unless otherwise noted.
2. Dimensioning and Tolerancing per ANSI Y14.5M-1994.
3. This drawing conforms to the JEDEC Solid State Outline MO-220,
variation WGGD except for custom features D2, E2, Z, Y, and L which are
toleranced per supplier designation.
4. Recommended card reflow profile is per the JEDEC/IPC J-STD-020
specification for Small Body Components.
Rev. 1.0
49
Si3484
8. PCB Land Pattern
Figure 14. Typical QFN-24 PCB Land Pattern
50
Rev. 1.0
Si3484
Table 27. QFN-24 PCB Land Pattern Dimensions
Dimension
MIN
MAX
C1
3.90
4.00
C2
3.90
4.00
E
0.50 BSC
X1
0.20
0.30
X2
2.70
2.80
Y1
0.65
0.75
Y2
2.70
2.80
Notes:
General
1. All dimensions shown are in millimeters (mm) unless otherwise noted.
2. This land pattern design is based on the IPC-7351 guidelines.
Solder Mask Design
3. All metal pads are to be non-solder mask defined (NSMD). Clearance
between the solder mask and the metal pad is to be 60mm minimum,
all the way around the pad.
Stencil Design
4. A stainless steel, laser-cut and electro-polished stencil with trapezoidal
walls should be used to assure good solder paste release.
5. The stencil thickness should be 0.125mm (5 mils).
6. The ratio of stencil aperture to land pad size should be 1:1 for all
perimeter pads.
7. A 2x2 array of 1.10mm x 1.10mm openings on 1.30mm pitch should
be used for the center ground pad.
Card Assembly
8. A No-Clean, Type-3 solder paste is recommended.
9. The recommended card reflow profile is per the JEDEC/IPC J-STD020 specification for Small Body Components.
Rev. 1.0
51
Si3484
9. Top Marking Diagram
Figure 15. Top Marking Diagram
Table 28. Top Marking Explanation
Pin 1 Identifier
Circle, 0.5 mm diameter
Product ID
3484A
Line 2 Marking:
Firmware revision
01 = Firmware revision 01
Line 3 Marking:
TTTTT = Trace Code
Manufacturing code characters from the
Markings section of the Assembly Purchase
Order form
YYWW+ = Date Code
YY = Last two digits of current year
WW = Current Work Week
Lead Free Designator
+
Line 1 Marking:
Line 4 Marking:
52
Rev. 1.0
Smart.
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