Question regarding using TPM channel for the TPM external clock input

mcu_guy2525 — Wed, 16 May 2012 20:45:19 GMT

I am working with MC9S08SG32 part.

The spec indicates that you can utilize a TPM channel as the input for the TPM external clock signal.

This part allows TPM channels to be routed to different pins. In the case of TPM1C0, it may be routed to either PTC0 or PTA0.

If I configure TPM1C0 to use PTC0 and use TPM1C0 for the external clock, will the external clock signal also be present on the alternate pin for this channel (PTA0)? I ran the test and it looks like it is present on both pins. Is there any method to restrict the signal to a single pin?

Re: Question regarding using TPM channel for the TPM external clock input

bigmac — Thu, 17 May 2012 22:34:56 GMT

Hello, and welcome to the forum.

Since TCLK is a lower priority, alternate pin function to TPM1CH0, it would be intuitive that TCLK should follow the the repositioning of the channel pin - is this what you have observed?

However, this would seem to be at odds with the datasheet, in Table 2.1. Here, TCLK is shown to be associated with PTA0 only, as an Alt 3 priority. What functionality have you observed for the PTA0 pin, after PTC0 becomes the TPM1C0 channel pin?

Perhaps you should generate a Service Request directly with Freescale, to have the matter clarified. If the datasheet does contain an error or ambiguity, this can be corrected for a future release of the document.

Regards,

Mac

topic Re: Question regarding using TPM channel for the TPM external clock input in 8-bit Microcontrollers

Question regarding using TPM channel for the TPM external clock input

Re: Question regarding using TPM channel for the TPM external clock input