JTAG Port
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Bottom view of Barracuda module with probable JTAG pins: . . O ??? O TMS/TDI . . . O TDI/TMS . . . O ??? O ???
Diagnostic
Presently, a possible location for the JTAG port has been identified, but which pin is which has not.
JTAG consists of 4 or 5 pins:
- TRST - A Reset line.
- TDI - Data In
- TDO - Data Out
- TMS - The Mode Select pin, which actually drives the JTAG TAP Controller around a simple state machine.
- TCK - Clock
And Is Driven by a State Machine
Pin identification without risk of re-programming
TDO will have to be identified by impedence / voltage level testing.
- TCK: Burst Clock for period of test
- TDI: 111111111111111111
- TMS: 011111011000000000
1) TDI