AVR using JTag pins

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Hi,

Could I use AVR JTag pins in my application circuit when debugging using JTag?

Adding resistors to separate?

Thanks!

Re: AVR using JTag pins
These comments are intended to be my own opinion and they
may, or may not be shared by my employer, Atmel Sweden.

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JTag?
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I do not think so.
--
Best Regards
Ulf at atmel dot com



Re: AVR using JTag pins
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So I cannot debug when I use SPI in ATMega16!

Re: AVR using JTag pins



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On the ATmega16, the SPI port is on PB4-7 and the debug port in on port
PC2-5.

What is the problem again ???

Yes, you will lose port bits PC2-5 when using the JTAG port.


hamilton

Re: AVR using JTag pins
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Thanks!

Re: AVR using JTag pins
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I found in the JTagIce manual there is a section saying the following:

Figure 2-2 shows which JTAG lines should be connected to the target
AVR to ensure correct operation. To avoid drive contention on the
lines, place series resistors between the JTAG lines and external
circuitry. The value of the resistor should not exceed the maximum
ratings and sink or source to much current. See Section 5.4 for a
detailed description of the hardware.

Is it true to place series resistors between the JTAG lines and
external circuitry so that I can debug the IO pins using JTagICE?

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