MPC8640D JTAG problem

[jeffcao]

I am facing issue while connecting JTAG with MPC8640 board.I am using WINDRIVER debug 8640D.

in the process "attemping JTAG communication " it display fail.

what might be the problem?

I found it can distinguish two core。

but it cannt be conmmunicate with the  2 core 

[alexander_yakov]

Debug interface is a part of core, so if the core is disabled, debug interface is also inaccessible.

This is the most frequent reason for the core to not respond to debugger commands.

Have a great day,
Alexander
TIC

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[jeffcao]

you say ”This is the most frequent reason for the core to not respond to debugger command”

How can I prove this viewpoint.

power on sequence I have been check 

No abnormality found

[alexander_yakov]

In addition to power supply, there are a lot of other things to check:

1. Reset configuration

2. Clock frequency and clock settings

3. etc