Intel
®
81341 and 81342—Test Logic Unit and Testability
Intel
®
81341 and 81342 I/O Processors
Developer’s Manual
December 2007
1006
Order Number: 315037-002US
20.2
IEEE 1149.1 Standard Test Access Port (TAP)
The I/O processor contains test logic that is compatible with the IEEE Standard 1149.1-
2001 Test Access Port (TAP) and Boundary Scan Architecture. Logic that conforms to
this standard contains:
• Test Access Port (TAP):
— four inputs (
TDI
,
TMS
,
TRST#
and
TCLK
)
— single output (
TDO
).
• TAP controller
• Instruction register
• Group of test data registers
Each of these is described in more detail below.
shows a generic diagram for
logic conforming to the IEEE 1149.1 test standard.
Figure 169. IEEE 1149.1 Std. Block Diagram
TAP
Controller
(16-State)
Boundary Scan Register
Device ID Register
Design-Specific Data Registers
Bypass Register
Instruction Decode
Shift Register
Internal Logic
MUX
MUX
Instruction Bits
Test Data Registers
Intstruction Registers
M
od
e1
M
od
e4
M
od
e3
M
od
e2
S
e
le
ct
TCK*
Select
Shift
Reset*
ClockIR
ShiftIR
UpdateIR
Reset*
ClockDR
ShiftDR
UpdateDR
TMS
TCK
Device Outputs
TDO
TDI
Device Inputs
TRST*
B6311-01