Maxim Integrated MAX31782 - Manual (Page 131)

MaximIntegrated 16-3
MAX31782 User’s Guide
Revision 0; 8/11
16.1TAPController
The TAP controller is a synchronous state machine that responds to changes at the TMS and TCK signals . Based on its
state transition, the controller provides the clock and control sequence for TAP operation . The performance of the TAP
is dependent on the TCK clock frequency . The maximum TCK clock frequency should be limited to 1/8 the system clock
frequency . This section provides a brief description of the state machine and its state transitions . The state diagram in
Figure 16-2 summarizes the transitions caused by the TMS signal sampling on the rising edge at TCK . The TMS signal
value is presented adjacent to each state transition in the figure .
Figure 16-2. TAP Controller State Diagram
TEST-LOGIC-RESET
RUN-TEST-IDLE SELECT-DR-SCAN
EXIT2-DR
CAPTURE-DR
SHIFT-DR
EXIT1-DR
PAUSE-DR
UPDATE-DR
SELECT-IR-SCAN
EXIT2-IR
CAPTURE-IR
SHIFT-IR
EXIT1-IR
PAUSE-IR
UPDATE-IR
1
0
1 1 1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0 0
1 1
0 0