Trace on MIMXRT1020

[chriscowdery]

Hi All,

 I would like to use Instruction Trace over the Serial Wire interface.

I cannot find any documentation for this, and the MIMXRT1021-EVK does not support it.

The Reference Manual is not clear regarding which pins to use.

Specifically:

1. Which pins are required (SWDIO,SWCLK,SWO)?

2. What configuration is required in firmware?

Is there an Application Note?

Thanks,

Chris.

[jingpan]

Hi Chris,

SWDIO and SWDCLK is used to debug (SWD port is like JTAG). TRACECLK/TRACEDATA is used for tace function.

Regards,

Jing

[chriscowdery]

Hi Jing,

 Is that correct?

https://www.segger.com/products/debug-probes/j-link/accessories/adapters/19-pin-cortex-m-adapter/ 

Shows SWO should be connected to TDO.

If I connect SWO to TDO (on the SJC (System JTAG Controller), will I get Trace? If not, what does it do?

Or do I need TRACECLK & TRACEDATA[3..0] ?

What is the difference?

Thanks,

Chris.

[chriscowdery]

Hi,

 I have been reading all day on this subject, and will make a new post.

Chris.

[jingpan]

Hi,

1. RT series default use SWD as debug protocol. SWD only use SWDIO and SWDCLK. TDO is used by JTAG. If you want to use JTAG, you should change eFUSE.

2. Yes, TDO share pin with SWO.

3. SWO works alone. It needn't other clock signal.

4. TRACECLK works with TRACEDATA[x]. TRACE can be 1-bit (TRACECLK+TRACEDATA00)  or 4-bit(TRACECLK+TRACEDATA[00~03]). I'm sure 1-bit mode can work on RT1020. But I'm not sure if 4-bit can work.

Regards,

Jing