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?

I do not think so.

So I cannot debug when I use SPI in ATMega16!

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

Thanks!

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?