
Debug in Depth
ARM DDI 0029G Copyright © 1994-2001. All rights reserved. B-9
B.5 Public instructions
Table B-1 lists the public instructions.
In the following instruction descriptions, 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.
The following sections describe:
• EXTEST (0000) on page B-9
• SCAN_N (0010) on page B-10
• SAMPLE/PRELOAD (0011) on page B-10
• RESTART (0100) on page B-10
• CLAMP (0101) on page B-11
• HIGHZ (0111) on page B-11
• CLAMPZ (1001) on page B-11
• INTEST (1100) on page B-12
• IDCODE (1110) on page B-12
• BYPASS (1111) on page B-12.
B.5.1 EXTEST (0000)
The selected scan chain is placed in test mode by the EXTEST instruction.
Table B-1 Public instructions
Instruction Binary Hexadecimal
EXTEST 0000 0x0
SCAN_N 0010 0x2
SAMPLE/PRELOAD 0011 0x3
RESTART 0100 0x4
CLAMP 0101 0x5
HIGHZ 0111 0x7
CLAMPZ 1001 0x9
INTEST 1100 0xC
IDCODE 1110 0xE
BYPASS 1111 0xF
Comments to this Manuals