S32K142 Custom Board Programming Issues

[talha_uyar]

Hi,

We have designed a custom board for our S32K142. I am trying to program it using the OpenSDA on my S32K142 EVB. I have connected J14's Pin_2, Pin_4, Pin_10, and Pin_3 (SWD_DIO, SWD_CLK, RST_TGTMCU_B, and GND) to the custom board. Then, I have tried to flash something to the custom board but I have failed.

When I measure the RST_TGTMCU_B with an oscilloscope I see that it is not held low and instead oscillates between 2.5V and 0V (see attached image). I think the microcontroller is resetting itself but I don't know why. What could be the issue here? We have connected a 24 MHz XTAL to PTB6 and PTB7. Could this be the issue?

Thanks for all the help

[lukaszadrapa]

Hi,

I'm afraid this is not expected use-case. You are talking to two microcontrollers at the same time, so there could be a conflict between the signals. Better solution is to use debug probe like:

http://www.pemicro.com/products/product_viewDetails.cfm?product_id=15320168&productTab=1

or

http://www.pemicro.com/products/product_viewDetails.cfm?product_id=15320143&productTab=1

Regards,

Lukas

[talha_uyar]

Hi Lukas,

Sorry for the confusion but the RESET pin's measurements are there whether I connect the debugger or not. The microcontroller's Reset pin is always showing the described behavior when I connect it to power. Can you look into the possible causes of this?

I have also tried to program the microcontroller with J-Link using SWD but could not program it.

[lukaszadrapa]

Hi,

some useful hints for recovery can be found in this thread:

https://community.nxp.com/t5/S32K/S32K142-EVB-board-bricks/m-p/1157622

Do you mean you replaced original 8MHz crystal? It should be no problem, the frequency can be 4 - 40MHz.

Regards,

Lukas

[talha_uyar · Accepted solution]

Hi Lukas,

I have solved my problem and it was rather simple. We had a capacitor connected to the reset pin and the S32K142 was resetting itself since it had no code. This was resulting in the behavior I have posted here. I removed the capacitor and used JLink to flash. I also added the line "monitor reset" to the debugger's startup tab in S32 DS as described here . The JLink successfully flashed the S32K142.

Thanks,

M. Talha Uyar