I2C1 SDA SetMux off of SD_B1_05 causes crash

[jautry]

If I do a SetMux for I2C1 SDA off of GPIO_SD_B1_05 the XPRESSO/JLINK debug locks up.  If I use AD_B1_01, there is no problem.  If I single step, it then seems to jump over instructions and loop back over itself, so the debugger seems to be corrupted at that point.

[nickwallis · Accepted solution]

See this thread for an explanation:

https://community.nxp.com/t5/i-MX-RT/target-crashes-writing-to-register-SW-MUX-CTL-PAD-GPIO-SD-B1-05...

-Nick

[jautry]

I also tried just to add a SetPinMux for SD_B1_05 to the flexspi_nor test software that was working and it now fails also.  Moving to AD_B1_01 seems to work fine for the SDA signal but I will have to juggle board wiring as I am short GPIOs if I cannot use that one for some reason.  Setting SD_B1_05 to SDA or plain GPI use does not matter, it causes problems anyway.  Is there something special about this pin??

iMxRT1061A