MPC5xxx中的主题 MPC5604E - cannot set GPIOs

MPC5604E - cannot set GPIOs

janberan — Tue, 11 Aug 2015 08:20:15 GMT

Hi all,

I have been working with MPC5604E in our company project and I have the following problem: I need to set a few pins as output GPIOs so I write 0x0200 to appropriate PCR registers. However, for certain pins this write is ignored and the PCR value remains unchanged.

My further experiments discovered that this happens if and only if the pin has defined no output alternate function besides GPIO. Moreover, I am able to set all the PCR register bits except OBE. Just to make it clear, I can successfully set OBE bit for all other pins.

I am confused since the MPC5604E reference manual marks all the pins to be configurable as GPIO I/O. Am I missing something?

Best Regards,

Jan Beran

Re: MPC5604E - cannot set GPIOs

martin_kovar — Tue, 11 Aug 2015 12:45:22 GMT

Hi Jan,

Look to the reference manual chapter 3.2 Signal Properties Summary, Table 4 pin muxing. If the pin has input direction only (PCR20 for example), then it is not possible to set OBE.

Regards,

Martin

Re: MPC5604E - cannot set GPIOs

janberan — Tue, 11 Aug 2015 14:55:07 GMT

Hi Martin,

Thanks for your answer! I see the problem now - I have been using an old version of the reference manual (rev. 3, 21/06/12) and in that document even PCR[20] is marked as GPIO I/O. So I downloaded the revision 5 of the manual (07/2015 hopefully the latest) and everything makes sense now.

Best Regards,

Jan Beran