
10-6
PENTIUM® PRO PROCESSOR TEST ACCESS PORT (TAP)
10.2.2.
Accessing the Data Registers
The test data registers in the Pentium Pro processor are designed in the same way as the instruc-
tion register, with components (i.e. either the “capture” or “update” functionality) removed from
the basic structure as needed. Data registers are accessed just as the instruction register is, only
using the “select-DR-scan” branch of the TAP finite state machine in Figure 10-2. A specific
data register is selected for access by each TAP instruction. Note that the only controller states
in which data register contents actually change are Capture-DR, Shift-DR, Update-DR and Run-
Test/Idle. For each of the TAP instructions described below, therefore, it is noted what operation
(if any) occurs in the selected data register in each of these four states.
10.3.
INSTRUCTION SET
Table 10-1 contains descriptions of the encoding and operation of the TAP instructions. There
are seven 1149.1-defined instructions implemented in the Pentium Pro processor TAP. These in-
structions select from among four different TAP data registers – the boundary scan, BIST result,
device ID, and bypass registers.
Figure 10-5. TAP Instruction Register Access
E
x
it1
-I
R
Up
d
a
te
-I
R
Run-
T
est
/I
dl
e
Te
st
-L
o
g
ic
-R
es
e
t
Run-
T
e
st
/I
dl
e
Sel
e
ct
-D
R
-S
can
Sel
e
ct
-I
R-
Sca
n
Ca
pt
u
re
-I
R
S
h
if
t-
IR
“IDCODE”
“BYPASS
TCK
TMS
TAP
controller
state
TDO
Instruc-
tion
TDI
Содержание Pentium Pro Family
Страница 17: ...1 Component Introduction ...
Страница 26: ...2 Pentium Pro Processor Architecture Overview ...
Страница 27: ......
Страница 36: ...3 Bus Overview ...
Страница 62: ...4 Bus Protocol ...
Страница 105: ...5 Bus Transactions and Operations ...
Страница 126: ...6 Range Registers ...
Страница 131: ...7 Cache Protocol ...
Страница 135: ...8 Data Integrity ...
Страница 148: ...9 Configuration ...
Страница 161: ...10 Pentium Pro Processor Test Access Port TAP ...
Страница 172: ...11 Electrical Specifications ...
Страница 201: ...12 GTL Interface Specification ...
Страница 229: ...13 3 3V Tolerant Signal Quality Specifications ...
Страница 233: ...14 Thermal Specifications ...
Страница 239: ...15 Mechanical Specifications ...
Страница 241: ...15 2 MECHANICAL SPECIFICATIONS s Figure 15 1 Package Dimensions Bottom View ...
Страница 252: ...16 Tools ...
Страница 260: ...16 8 TOOLS Figure 16 4 Generic MP System Layout for Debug Port Connection ...
Страница 264: ...17 OverDrive Processor Socket Specification ...
Страница 290: ...A Signals Reference ...
Страница 320: ...Index ...
Страница 328: ......