10-7
PENTIUM® PRO PROCESSOR TEST ACCESS PORT (TAP)
TAP instructions in the Pentium Pro processor are 6 bits long. For each listed instruction, the
table shows the instruction’s encoding, what happens on the Pentium Pro processor pins, which
TAP data register is selected by the instruction, and the actions which occur in the selected data
register in each of the controller states. A single hyphen indicates that no action is taken. Note
that not all of the TAP data registers have a latched parallel output (i.e. some are only simple
shift registers). For these data registers, nothing happens during the Update-DR controller state.
NOTE:
1. The Pentium
®
Pro processor must be reset after this command.
Full details of the operation of these instructions can be found in the 1149.1 standard.
The only Pentium Pro processor TAP instruction which does not operate exactly as defined in
the 1149.1 standard is RUNBIST. In the 1149.1 specification, Rule 7.9.1(b) states that: “Self-
test mode(s) of operation accessed through the RUNBIST instruction shall execute only in the
Run-Test/Idle controller state.” In the Pentium Pro processor implementation of RUNBIST, the
execution of the Pentium Pro processor BIST routine will not, however, stop if the Run-Test/Idle
state is exited before BIST is complete. In all other regards, the Pentium Pro processor
RUNBIST instruction operates exactly as defined in the 1149.1 specification.
Table 10-1. 1149.1 Instructions in the Pentium
®
Pro Processor TAP
TAP
Instruction
Opcode
Pentium
®
Pro
processor
pins
driven
from:
Data
Register
Selected
Action during:
RT/Idle
Capture-DR
Shift-DR
Update-DR
EXTEST
000000
Boundary
scan
Boundary
scan
-
sample all
Pentium
®
Pro
processor pins
shift data
register
update
data
register
SAMPLE/
PRELOAD
000001
-
Boundary
scan
-
sample all
Pentium Pro
processor pins
shift data
register
update
data
register
IDCODE
000010
-
Device ID
-
load unique
Pentium Pro
processor ID
code
shift data
register
-
CLAMP
000100
Boundary
scan
Bypass
-
reset
bypass reg
shift data
register
-
RUNBIST
000111
Boundary
scan
Bist result
BIST
starts1
capture
BIST result
shift data
register
-
HIGHZ
001000
floated
Bypass
-
reset
bypass reg
shift data
register
-
BYPASS
111111
-
Bypass
-
reset
bypass reg
shift data
register
-
Reserved
all other
rsvd
rsvd
rsvd
rsvd
rsvd
rsvd
Summary of Contents for Pentium Pro Family
Page 17: ...1 Component Introduction ...
Page 26: ...2 Pentium Pro Processor Architecture Overview ...
Page 27: ......
Page 36: ...3 Bus Overview ...
Page 62: ...4 Bus Protocol ...
Page 105: ...5 Bus Transactions and Operations ...
Page 126: ...6 Range Registers ...
Page 131: ...7 Cache Protocol ...
Page 135: ...8 Data Integrity ...
Page 148: ...9 Configuration ...
Page 161: ...10 Pentium Pro Processor Test Access Port TAP ...
Page 172: ...11 Electrical Specifications ...
Page 201: ...12 GTL Interface Specification ...
Page 229: ...13 3 3V Tolerant Signal Quality Specifications ...
Page 233: ...14 Thermal Specifications ...
Page 239: ...15 Mechanical Specifications ...
Page 241: ...15 2 MECHANICAL SPECIFICATIONS s Figure 15 1 Package Dimensions Bottom View ...
Page 252: ...16 Tools ...
Page 260: ...16 8 TOOLS Figure 16 4 Generic MP System Layout for Debug Port Connection ...
Page 264: ...17 OverDrive Processor Socket Specification ...
Page 290: ...A Signals Reference ...
Page 320: ...Index ...
Page 328: ......