MCF5328 PWM GPIO bits

powie_freescale — Thu, 14 Jul 2011 02:40:21 GMT

I'm confused by the MCF5328 family documentation and header files regarding the PWM1/3/5/7 pins used as GPIO. The MCF5329 reference manual (rev 3) shows only bits 2,3,4 and 5 being used in the PODR_PWM, PDDR_PWM and PPDSDR_PWM registers, which does match the PWM "bits" 1/3/5/7 (which are shown as GPIO signals PWM1/3/5/7 in table 2-1). For the PPDSDR_PWM register it specifically states that these are the controls for signals PWM2/3/4/5 - which does not match the actual PWM numbers. Looking in the header files from Freescale - it also uses the 2/3/4/5 bit numbers for these registers - not matching the PWM1/3/5/7 numbers.

Can anybody tell me the correct meanings of the bits in the PODR_PWM, PDDR_PWM and PPDSDR_PWM registers for the MCF5328?

Thanks,

Paul Withers

Re: MCF5328 PWM GPIO bits

TomE — Thu, 14 Jul 2011 08:16:00 GMT

That looks like a cut-and-paste bug when those manuals were being assembled.

Searching shows those register and bit names only exist in the MCF5329 and MCF5373 manuals, so it doesn't immediately look like a chapter got pasted from an MCF52xx chip as I've seen before.

"bits 2,3,4 and 5 being used in the PODR_PWM, PDDR_PWM and PPDSDR_PWM" have been named as per the bits in that register, which is consistent for that chapter.

The PWM signals are named for their function.

I think the "proper fix" would be to change only the second column in "Table 2-1. MCF5327/8/9 Signal Information and Muxing" and "Table 13-1. MCF5327/8/9 Signal Information and Muxing" to something like:

Signal Name GPIO

--------------------

PWM7 PPWM5

PWM5 PPWM4

PWM3 PPWM3

PWM1 PPWM2

Please write some code totest this out and then report back.

Tom

ColdFire/68K Microcontrollers and ProcessorsのトピックMCF5328 PWM GPIO bits

MCF5328 PWM GPIO bits

Re: MCF5328 PWM GPIO bits