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Debug Support
5.5.4
Public instructions
5-14
The following public instructions are supported:
In the descriptions that follow, TDI and TMS are sampled on the rising edge of TCK
and all output transitions on TDO occur as a result of the falling edge of TCK.
EXTEST (0000)
The selected scan chain is placed in test mode by the EXTEST instruction.
The EXTEST instruction connects the selected scan chain between TDI and TDO.
When the instruction register is loaded with the EXTEST instruction, all the scan cells
are placed in their test mode of operation.
In the CAPTURE-DR state, inputs from the system logic and outputs from the output
scan cells to the system are captured by the scan cells.
In the SHIFT-DR state, the previously captured test data is shifted out of the scan chain
via TDO, while new test data is shifted in via the TDI input. This data is applied
immediately to the system logic and system pins.
Copyright © 1998, 1999 ARM Limited. All rights reserved.
Table 5-1 Public instructions
Instruction
EXTEST
SCAN_N
INTEST
IDCODE
BYPASS
CLAMP
HIGHZ
CLAMPZ
SAMPLE/PRELOAD
RESTART
Binary code
0000
0010
1100
1110
1111
0101
0111
1001
0011
0100
ARM DDI0145B
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