1300 Henley Court
Pullman, WA 99163
509.334.6306
www.store. digilent.com
JTAG-SMT3-NC Reference Manual
Revised September 6, 2018
This manual applies to the JTAG-SMT3-NC rev. A
Overview
The Joint Test Action Group (JTAG)-SMT3-NC is a compact, complete, and fully self-contained surface-mount
programming module for Xilinx field-programmable gate arrays (FPGAs). The module can be accessed directly from
all Xilinx Tools, including iMPACT, ChipScope™, Vivado, and EDK. Users can load the module directly onto a target
board and reflow it like any other component.
The JTAG-SMT3-NC uses a 3.3V main power supply and independent Vref supplies to drive the JTAG and UART
signals. All JTAG signals use high speed 24mA three-state buffers that allow signal voltages from 1.8V to 5.5V, and
bus speeds up to 30MBit/sec. All UART signals use high speed 24mA buffers that allow signal voltages from 1.8V to
5.5V and bus speeds up to 12Mbaud. The JTAG bus can be shared with other devices as the SMT3-NC signals are
held at high impedance, except when actively driven during programming. The SMT3-NC module is CE certified and
fully compliant with EU RoHS and REACH directives. The module routes the USB D+ (DP) and D- (DM) signals out to
pads, providing the system designer with the ability to choose the type of USB connector and its location on the
system board.
•
•
•
•
•
•
•
•
The JTAG-SMT3-NC.
DOC#: 410-357
•
Small, complete, all-in-one JTAG
programming/debugging solution for Xilinx
FPGAs with UART side channel
Compatible with Xilinx Tools
High-Speed USB 2.0 port that can drive JTAG bus
up to 30Mbit/sec (frequency settable by user)
Open drain buffer on PS_SRST_B pin allows
debugging software to reset the processor core
of Xilinx’s Zynq® platform
Dual channel USB controller provides
simultaneous access to both JTAG and UART
interfaces
Separate Vref for JTAG and UART signals allows
each interface to operate at difference voltages
(1.8V to 5.5V)
Small form-factor surface-mount module can be
directly loaded on target boards
USB D+ and D- signals routed to pads, allowing
USB connector to be placed anywhere on the
host PCB
VBUS_DETECT pin allows for reduced current
consumption when the module isn’t connected
to a PC
Copyright Digilent, Inc. All rights reserved.
Other product and company names mentioned may be trademarks of their respective owners.
Page 1 of 10
JTAG-SMT3-NC Reference Manual
Users can connect JTAG signals directly to the corresponding FPGA signals, as shown in Fig. 1. For best results,
mount the module over a ground plane on the host PCB. Although users may run signal traces on top of the host
PCB beneath the SMT3-NC, Digilent recommends keeping the area immediately beneath the SMT3-NC clear.
Note: Keep the impedance between the SMT3-NC and FPGA below 100 Ohms to operate the JTAG at maximum
speed. Note: If series resistors are used, they should be placed near the transmitting end in order to minimize
reflections.
In addition to supporting JTAG, the JTAG-SMT3-NC also features a UART Interface that allows communication with
UART peripherals (see Fig. 2). The UART interface is presented as a virtual com port on the host PC, supports baud
rates up to 12Mbaud, and has an independent voltage reference which allows it to interface with devices
operating at voltages between 1.8V and 5.5V.
1
Software Support
The JTAG-SMT3-NC has been designed to work seamlessly with Xilinx’s ISE® (iMPACT, ChipScope, EDK, and eFuse)
and Vivado tool suites. The most recent versions of ISE and Vivado include all of the drivers, libraries, and plugins
necessary to communicate with the JTAG-SMT3-NC. At the time of writing, the following Xilinx software included
support for the SMT3: Vivado 2017.1+, Vivado 2016.1+, Vivado 2015.1+, Vivado 2014.1+, and ISE 14.1+. The SMT3NC is also compatible with ISE 13.1 - 13.4; however, these versions of ISE do not include all of the libraries, drivers,
and plugins necessary to communicate with the SMT3-NC. In order to use the JTAG-SMT3-NC with these versions
of ISE, version 2.5.2 or higher of the Digilent Plugin for Xilinx Tools package must be downloaded from the Digilent
website and the ISE13 plugin must be manually installed as described in the included documentation.
In addition to working seamlessly with all Xilinx tools, Digilent’s Adept software and the Adept software
development kit (SDK) support the SMT3-NC module. For added convenience, customers may freely download the
SDK from Digilent’s website. This Adept software includes a full-featured programming environment and a set of
public application programming interfaces (API) that allow user applications to directly drive the JTAG chain.
With the Adept SDK, users can create custom applications that will drive JTAG ports on virtually any device. Please
see the Adept SDK reference manual for more information.
Copyright Digilent, Inc. All rights reserved.
Other product and company names mentioned may be trademarks of their respective owners.
Page 2 of 10
JTAG-SMT3-NC Reference Manual
2
PS_SRST_B Pin
When customers use the JTAG-SMT3-NC to interface the scan chain of Xilinx’s Zynq platform, they should connect
the PS_SRST_B pin of the SMT3-NC to the Zynq’s PS_SRST_B pin. This connection allows the Xilinx Tools to reset
the Zynq’s processor core at various times during debugging operations. The PS_SRST_B pin on the SMT3-NC is
driven by an open drain buffer that is capable of sinking up to 32mA of current. Customers who connect this pin
must provide an external pull-up to the appropriate supply rail. A pull-up resistor between 1K - 100K Ohms is
recommended. Please see the following “Application Examples” section for more information.
3
VBUS_DETECT Pin
The VBUS_DETECT pin is used by the USB controller to determine when VBUS is present. When a logic ‘0’ is
detected on this pin, the USB controller is forced into suspend mode. This prevents the SMT3-MC from forcing
current down the USB lines when the host or the hub is powered off. Additionally, it results in reduced current
consumption from the module. Connect VBUS to the VBUS_DETECT pin using a resistor divider, similar to the one
in Fig. 3 shown below.
4
Application Examples
4.1
Example 1: Interfacing a Zynq-7000
Figure 4 demonstrates how to connect the JTAG-SMT3-NC to Xilinx’s Zynq-7000 silicon. Please note that VCCO_0
and VCCO_MIO1 may be powered by the same supply or by different supplies. The PS_SRST_B pin of the SMT3NC is driven by an open drain buffer and therefore an external open drain buffer is not required to add an optional
reset button.
Copyright Digilent, Inc. All rights reserved.
Other product and company names mentioned may be trademarks of their respective owners.
Page 3 of 10
JTAG-SMT3-NC Reference Manual
4.2 Example 2: Interfacing a Zynq-7000 while retaining the Xilinx
JTAG Header
Figure 5 below demonstrates how to connect the JTAG-SMT3-NC to Xilinx’s Zynq-7000 silicon alongside Xilinx’s 14pin JTAG header. In this example, an open drain buffer allows both the SMT3-NC and Xilinx JTAG Header to drive
the PS_SRST_B pin, which may operate a different voltage than the Zynq’s JTAG pins.
Copyright Digilent, Inc. All rights reserved.
Other product and company names mentioned may be trademarks of their respective owners.
Page 4 of 10
JTAG-SMT3-NC Reference Manual
5
Supported Target Devices
The JTAG-SMT3-NC is capable of targeting the following Xilinx devices:
•
•
•
•
•
•
Xilinx FPGAs
Xilinx Zynq-7000
Xilinx CoolRunner™/CoolRunner-II CPLDs
Xilinx Platform Flash ISP configuration PROMs¹, ²
Select third-party SPI PROMs¹, ²
Select third-party BPI PROMs¹, ²
The following devices cannot be targeted by the JTAG-SMT3-NC:
•
•
•
Xilinx 9500/9500XL CPLDs
Xilinx 1700 and 18V00 ISP configuration PROMs
Xilinx FPGA eFUSE programming
Remote device configuration is not supported for the JTAG-SMT3-NC when used with Xilinx’s iMPACT software.
¹ — Note: Please see the “Introduction to Indirect Programming – SPI or BPI Flash Memory” help topic in iMPACT for
a list of supported FPGA/PROM combinations.
² — Note: Please see the “Configuration Memory Support” section of Xilinx UG908 for a list of the FPGA/PROM
combinations that Vivado supports.
Copyright Digilent, Inc. All rights reserved.
Other product and company names mentioned may be trademarks of their respective owners.
Page 5 of 10
JTAG-SMT3-NC Reference Manual
5.1
Programming Solutions Comparison Chart
Max Speed
Voltage Range
Xilinx Native Support
Xilinx Plug-in Support
Digilent Adept Support
PC Interface
Onboard USB Connector
Host Board Connector
Interface
4-Wire JTAG
2-Wire JTAG
Zynq-7000 PS_SRST Support
SPI Support
Independent UART Channel
6
JTAG-SMT3-NC
30 MHz
1.8V – 5V
ISE 14.1+
Vivado 2014.1
ISE 13.1+
YES
USB
YES
18-pad SMT
JTAG-SMT2
30 MHz
1.8V – 5V
ISE 14.1+
Vivado 2013.1+
ISE 13.1+
YES
USB
YES
11-pad SMT
JTAG-SMT2-NC
30 MHz
1.8V – 5V
ISE 14.1+
Vivado 2013.1+
ISE 13.1+
YES
USB
NO
13-pad SMT
YES
NO
YES
NO
YES
YES
YES
YES
YES
NO
YES
YES
YES
YES
NO
Pinout Table
Pin Number
1
2
3
4
5
6
7
8
9
Pin Name
GND
VREF_UART
CTS
RTS
RXD
TXD
GND
VREF_JTAG
PS_SRST_B
Pin Number
10
11
12
13
14
15
16
17
18
Copyright Digilent, Inc. All rights reserved.
Other product and company names mentioned may be trademarks of their respective owners.
Pin Name
TCK
TDO
TDI
TMS
GND
VDD
USB_DM
USB_DP
VBUS_DETECT
Page 6 of 10
JTAG-SMT3-NC Reference Manual
7
Mechanical Information
8
General USB Signal Routing Guidelines
•
•
Maintain a differential impedance of 90 Ohms between the DP and DM signals.
Keep DP and DM trace lengths within 50 mils of each other.
Copyright Digilent, Inc. All rights reserved.
Other product and company names mentioned may be trademarks of their respective owners.
Page 7 of 10
JTAG-SMT3-NC Reference Manual
•
•
•
•
•
•
8.1
Minimize DP and DM signal trace length. Keeping the trace length below 3 inches is recommended.
When possible, route DP and DM on the plane closest to the ground plane.
When possible, avoid routing the DP and DM signals through vias. If vias cannot be avoided, then keep
them small and place the DP and DM traces on the same layer.
When possible, avoid routing other traces near DP and DM.
When possible, minimize or avoid the use of bends in the DP and DM traces. If 90 degree bends are
necessary, then use two 45 degree turns or an arc instead of a single 90 degree turn.
Do NOT route DP or DM near oscillators, crystals, switching regulators, clock generators, or inductors.
Absolute Maximum Ratings
Symbol
Vdd
Vref
VIO
IIK,IOK
IOUT
TSTG
ESD
8.2
Parameter
Operating supply voltage
I/O reference/supply voltage
Signal Voltage
TMS, TCK, TDI, TDO, TXD, RXD, RTS, CTS,
PS_SRST_B
DC Input/Output Diode Current
DC Output Current
Storage Temperature
Human Body Model JESD22-A114
Charge Device Model JESD22-C101
Condition
Min
-0.3
-0.3
-0.3
VIO < -0.3V
Max
4.0
6
6
-50
VIO > 6V
+20
-10
±50
+60
4000
2000
Unit
V
V
V
mA
mA
ºC
V
V
DC Operating Characteristics
Symbol
Vdd
VREF_JTAG
VREF_UART
TDO, RXD, CTS
VBUS_DETECT
TMS, TCK, TDI
TXD, RTS
PS_SRST_B
TA
Symbol
Parameter
Operating supply voltage
JTAG I/O reference/supply
voltage
UART I/O reference/supply
voltage
Input High Voltage (VIH)
Input Low Voltage (VIL)
Input High Voltage (VIH)
Input Low Voltage (VIL)
Output High (VOH)
Output Low (VOL)
Output High (VOH)
Output Low (VOL)
Output Low (VOL)
Operating Temperature
Parameter
Min
2.97
1.65
Typ
3.3
3.3
Max
3.63
5.5
1.65
3.3
5.5
0.75 x Vref
0
2.0
0
0.78 x Vref
0
0.75 x Vref
0
0
-40
Min
Copyright Digilent, Inc. All rights reserved.
Other product and company names mentioned may be trademarks of their respective owners.
0.95 x Vref
0.05 x Vref
Typ
5.5
0.55
Vdd
0.8
Vref
0.55
Vref
0.55
0.55
85
Max
Page 8 of 10
JTAG-SMT3-NC Reference Manual
9
AC Operating Characteristics
The JTAG-SMT3-NC’s JTAG signals operate according to the timing diagram in Fig. 7. The SMT3-NC supports
JTAG/TCK frequencies from 30 MHz to 8 KHz at integer divisions of 30 MHz from 1 to 3750. Common frequencies
include 30 MHz, 15 MHz, 10 Mhz, 7.5 MHz, and 6 MHz (see Table 2). The JTAG/TCK operating frequency can be set
within the Xilinx tools.
Note: Please refer to Xilinx’s iMPACT documentation for more information.
10
Mounting to Host PCBs
The JTAG-SMT3-NC module has a moisture sensitivity level (MSL) of 3. It is suitable for reflow for up to 168 hours
without additional drying.
The factory finishes the JTAG-SMT3-NC signal pads with the ENIG process using 2u” gold over 150u” electroless
nickel. This makes the SMT3-NC compatible with most mounting and reflow processes (see Fig. 8). The binding
force of the solder is sufficient to hold the SMT3-NC firmly in place, so mounting should require no additional
adhesives.
Copyright Digilent, Inc. All rights reserved.
Other product and company names mentioned may be trademarks of their respective owners.
Page 9 of 10
JTAG-SMT3-NC Reference Manual
11
Packaging
Digilent ships quantities under 40pcs individually packaged in antistatic bags. Digilent will pack and ship larger
quantities in groups of 40 positioned in an antistatic bake tray (see Fig. 10). Trays will be packaged in an anti-static
vacuum sealed bag. We also offer to bake them before shipping for an additional cost per 40pc lot.
Copyright Digilent, Inc. All rights reserved.
Other product and company names mentioned may be trademarks of their respective owners.
Page 10 of 10