Ethernet MII pins and JTAG Trace pins are Multiplexed in K60 and K64 controllers

[navinarsavad]

Hi All,

   I am trying to develop a code for ethernet using MII interface. But looking at the schematics I saw that the MII0_RXD3 is multiplexed with JTAG's TRACE_D1 pin and MII0_RXD2 is multiplexed with JTAG's TRACE_D0 pin. I am using  P&E 20 pin JTAG debugger for debugging. I need some advice with the following doubts:

1) Is there any safe way to route these pins to both ethernet and jtag? 

2) In such a scenario, I won't be able to debug the code right? 

3) If I use the JTAG to only load the program, then remove it and run the ethernet code, is it likely to cause any issues?

   I hope I have been clear enough about my questions. If you have any ideas, please share it here.

Regards,

Navinar Savad

[DavidS · Accepted solution]

Hi Navinar,

If your development tool doesn't support a trace feature then you don't need it.

If you look at the FRDM-K64F Freedom board it sets up the debug interface as a 10-pin connector.

The development tool is then setup to operate with SWD mode and not using the traditional JTAG signals which helps reduce the number of pins required for debugging and therefore leaves them available for Ethernet.

Regards,

David

[navinarsavad]

Hi David,

      Thanks for your help. I will follow your advice. :smileyhappy:

Regards,

Navinar