GS81284Z18/36B-250/200/167
JTAG TAP Instruction Set Summary
Instruction
EXTEST
Code
000
Description
Notes
1
Places the Boundary Scan Register between TDI and TDO.
Preloads ID Register and places it between TDI and TDO.
IDCODE
001
1, 2
Captures I/O ring contents. Places the Boundary Scan Register between TDI and
SAMPLE-Z
010
011
TDO.
1
1
Forces all RAM output drivers to High-Z.
Do not use this instruction; Reserved for Future Use.
Replicates BYPASS instruction. Places Bypass Register between TDI and TDO.
RFU
SAMPLE/
PRELOAD
Captures I/O ring contents. Places the Boundary Scan Register between TDI and
TDO.
100
101
110
111
1
1
1
1
GSI
GSI private instruction.
Do not use this instruction; Reserved for Future Use.
Replicates BYPASS instruction. Places Bypass Register between TDI and TDO.
RFU
BYPASS
Places Bypass Register between TDI and TDO.
Notes:
1. Instruction codes expressed in binary, MSB on left, LSB on right.
2. Default instruction automatically loaded at power-up and in test-logic-reset state.
Rev: 1.02 7/2010
23/29
© 2007, GSI Technology
Specifications cited are subject to change without notice. For latest documentation see http://www.gsitechnology.com.
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