TRK-MPC5634M Power supply issue - Safe Mode

[raphc63]

Hi,

I have a power supply issue on my starter kit TRK-MPC5634M

Datasheet : http://www.farnell.com/datasheets/1637030.pdf

Schematic : http://cache.freescale.com/files/microcontrollers/hardware_tools/schematics/TRKMPC5634MSCH.pdf

When I want to supply the board externally ( 9V-12V barrel connector ), the D4 LED turns RED ( safe mode ). When I supply the board by USB all is fine.

This LED D4 is connected to MCZ33905 ( Datasheet : http://datasheet.octopart.com/MCZ33905S5EK/R2-Freescale-Semiconductor-datasheet-8821163.pdf )

Informations about this "safe" is :

"Output of the safe circuitry. The pin is asserted LOW in case of a safe condition is detected (e.g.: software watchdog is not triggered, VDD low, issue on reset pin etc.). Open drain structure."

I checked th device VBAT, which is correct. For other condition I don't know how to check if there is an issue on reset pin or watchdog.

[martin_kovar · Accepted solution]

Hi,

Check jumper J1 and J5. If you want to use external power supply you have to fit jumper J1 into the correct position and especially check if jumper J5 is fitted. If the jumper J5 is not fitted, SBC chip is not in debug mode and watchdog resets the SBC chip(D4 LED turn on and D1 LED turn off).

Regards,

Martin

[raphc63]

Thanks Martin it works. I tried this debug method but my fault was too fit J5 and J4(DBG) jumper, J5 only works fine.