MPC5604B software reset

[283230333]

In MPC5644A , we can reset the software by the bit "SIU.SRCR.B.SSR" . Now we want to reset the MPC5604B in the same way , so how can I do it ?

[davidtosenovjan · Accepted solution]

Use the MC_ME module to enter the RESET mode (SW functional reset):

/* software reset */   

ME.MCTL.R = 0x00005AF0;

ME.MCTL.R = 0x0000A50F;

This sequence reset the device.

[283230333]

Ok , very thanks!  Another question ! The problem is still about 5604B. I have erased the shadow block of the 5604b , but didn't write a new correct data. So I can't access the device via the JTAG. But recently, I have also erased the shadow block of the 5644A , and also didn't write a new correct data. But i can still access the device via the JTAG by configure the BOOTCFG pin, and let the code run in the RAM.  So, can I  uncensorship the 5604B by the same way?

[davidtosenovjan]

Censorship is very sensitive thing. It is needed to use it very carefully, because an inappropriate usage can lead in making the device useless. If you accidentally erase shadow flash there is no chance to recover it (unless it had been though about before).

If your device is censored and you don’t have any pre-prepared recovery code located in the internal flash memory, there is no way how to unlock it and everything you can do is to order new sample, and re-solder it instead of the censored one.

Thus I would recommend to study following appnote:

http://cache.freescale.com/files/32bit/doc/app_note/AN3787.pdf

[283230333]

Thanks for your reply. Are there another way  can encrypted the device, and can't access the device via the JTAG?

[davidtosenovjan]

It works slightly different way on MPC5644A (and all MPC55xx) and MPC5604B (and most of 56xx).

Erased shadow flash means in case MPC5644A that device is censored. In case you switch to serial boot mode, you can access to the device over JTAG, but internal flash does not work (it means internal RAM target works, internal FLASH target does not).

In case MPC5604B device, in case shadow flash is erased, device is locked out permanently and neither JTAG access is allowed. Thus the device is broken and there is no other way how to repair it.

[alexvinchev]

Hi David,

is there document, similar to this one, but for MPC57xx family? I'm interested especially for MPC5748G.

[davidtosenovjan]

I am not aware of any document dealing with MPC57xx censorship. Unfortunately I don’t have experience with that implementation. You may try to submit new thread or case, maybe someone will help you.