AMD AMD5K86 - TMS (Test Mode Select)

AMD~
AMD5~6 Processor Technical Reference Manual 18524BjO-Mar1996
5.2.52
Summary
TDO (Test Data Output)
Output
TDO carries output data for testing on the Test Access Port
(TAP).
Driven and Floated
The processor drives TDO every falling TCK edge, but only
during the shiftjR and shift_DR states. It is floated at all other
times.
Details
5-130
TDO is always driven, except when floated and while RESET
or INIT is asserted.
Instructions are shifted out of the processor on TDO during the
shiftjR TAP state. Data are shifted out of the processor on
TDO during the shifcDR TAP state.
See the IEEE Standard Test Access Port and Boundary-Scan
Architecture (IEEE 1149.1)
specification for a description of
how the TAP signals and instructions are used for testing.
Bus Interface