Was bitten by the jtag fuse again

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#1
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Damm ...

Just spend 2.5 hr's debugging a LCD app on a M32 PORTC , couldn't get it to work :evil:

Then i remembered :oops: :oops:

Disabled the Jtag fuse , and 2.5 hr's wasted :cry: :cry:

/Bingo

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hehehe, I used 2 hours yesterday aftenoon, doing the same thing, some of the pins showed activity on the scope, and other pins were dead, then, whoops jtag enabled :)

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Is writing JTD in MCUCSR from the AVR code (compiled conditionally) perhaps an easier way to disable the JTAG than changing fuses?

As noted on page 226 you have to write JTD twice in four cycles.

Cliff

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clawson wrote:
Is writing JTD in MCUCSR from the AVR code (compiled conditionally) perhaps an easier way to disable the JTAG than changing fuses?

As noted on page 226 you have to write JTD twice in four cycles.

Cliff

Hmmm that was a neat option ...

Thnx Cliff

Btw. it's page 228 :-)

Atmel just updated the DS for M32,M8 & M88(family)

/Bingo

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The ability to disable the jtag at runtime is good. From a production standpoint that could save you the extra step of disabling the jtag fuse if you had no other fuses to modify.

Since I don't have a jtag, I don't know what the effect of disabling it at runtime does to your debug session. Given the same circuit with an LCD using those pins, I would assume you can't debug with jtag and have a working display at the same time anyway.