Example Using Pgnd In A Jtag Chain - Xilinx Platform Cable USB II Manual

X-Ref Target - Figure 16
TDO
TDI
TMS
TCK
V
CCAUX
2-mm
Connector
2
V
REF
8
TDO
10
TDI
TMS 4
6
TCK
(5)
13
PGND
(2)
*
GND
Notes:
1. Example implies that V
CCO
2. Attach the following 2-mm connector pins to digital ground: 3, 5, 7, 9, and 11.
3. The cable uses an open-drain driver to control the pseudo ground (PGND) signal — an external pull-up resistor is required.
4. Assumes that the multiplexor supply voltages pins are connected to V
5. Pin 13 is grounded on legacy Xilinx USB cables (models DLC9, DLC9G and DLC9LP), and Parallel Cable IV (model DLC7). These cables
need to be manually detached from the 2-mm connector to allow the primary configuration source to have access to the JTAG chain.
DS593 (v1.2.1) March 17, 2011
V
CCAUX
(1)
, V , and/or V for various devices in the JTAG chain are set to the same voltage.
CCJ CCAUX
Figure 16: Example Using PGND in a JTAG Chain
(4)
A
Y
B
S
(4)
A
Y
B
S
A
B
V
CCAUX
Required
1 KΩ
(3)
Pull-Up
.
CCAUX
www.xilinx.com
Platform Cable USB II
JTAG CHAIN
TDI
TMS
(4)
Y
S
TDO
TCK
MUX Truth Table
S Output
H Y = A
L Y = B
DS593_16_021408
16