JTAG debug mechanism

[Song Sam]

Li Yang-r58472 <LeoLi at freescale.com> wrote:

> As we know PowerPC use JTAG to debug CPU, which

But 8xx use BDM to debug CPU.So I wonder in which
situation or chips should we use BDM and JATG and
WHY??? For a embedded developer,he could more concern
about this point than JATG implementation process,I
guess.:-)

> implements a Boundary-Scan mechanism. It can manipulate any
> input/output signals of the CPU by a serial shift/scan process. But my
> question is how it can read/write the core registers and system memory
> as implemented by most JTAG emulators.

Any input is warmly welcome!

Best regards,

Sam

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