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Rev. 5.00, 09/03, page 651 of 760
22.4 UDI Operation
22.4.1 TAP Controller
Figure 22.2 shows the internal states of the TAP controller. State transitions basically conform
with the JTAG standard.
Test-logic-reset
Capture-DR
Shift-DR
Exit1-DR
Pause-DR
Exit2-DR
Update-DR
Select-DR-scanRun-test/idle
1
0
0
0
0
11 1
1
0
0
1
0
1
1
10
Capture-IR
Shift-IR
Exit1-IR
Pause-IR
Exit2-IR
Update-IR
Select-IR-scan
0
0
1
0
0
1
0
1
1
10
0
Figure 22.2 TAP Controller State Transitions
Note: The transition condition is the TMS value at the rising edge of TCK. The TDI value is
sampled at the rising edge of TCK; shifting occurs at the falling edge of TCK. The TDO
value changes at the TCK falling edge. The TDO is at high impedance, except with shift-
DR (shift-SR) and shift-IR states. During the change to TRST = 0, there is a transition to
test-logic-reset asynchronously with TCK.