Double edge clock to TPM in KL25 Reference Manual diagram?

[stevecolley65]

Two questions about the same diagram.

1. In Section 31.4.2 of the KL25 Reference Manual, Figure 31-78 shows the prescalar count changing on both edges of the "selected input clock". This section is in the TPM Functional Description. Is this an error in the diagram? It doesn't seem like double edge clocking is going on.  I see this in other documents for the TPM. BTW, My TPM is working as expected.

2. Also, in the diagram, what is "CNTIN = 0x0000" in the upper left corner? CNTIN is nowhere else in the manual.

Thanx!

Edit: I find the TPM seems to be derived from a module called a FlexTimer which has a CNTIN register (Counter Initial Setting). So, I think that answers question 2. The equivalent diagram in a FlexTimer description has proper clocking with changing count on only the rising edge. So, I think the diagram in question is simply incorrect on the clocking and the CNTIN was left after a copy-paste of the figure when used for the TPM. Thanx! 

[kerryzhou]

Hi Stephen Colley 

  Thank you for your interest in NXP kinetis product, I would like to provide service for you.

  Now, answer you two questions:

1. About the prescaler counter

   I think the figure is not correct enough.

  Take an example, if the input the TPM clock is 20Mhz, then the prescaler is 2, then the module counter clock is 20Mhz/2=10Mhz, it won't count for both edge.

  So, just ignore that figure.

2. Also, in the diagram, what is "CNTIN = 0x0000" in the upper left corner? CNTIN is nowhere else in the manual.

  CNTIN is the initial counter value for FTM, it has the specific register, and can set it. But to TPM, the CNTIN is fixed to 0.  You can consider CNTIN is 0, it is the initial counter value.

Wish it helps you!
Have a great day,
Kerry

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