Thomas Kobler

Selecting channel IO pin for external source of TPM - MC9S08DZ60

Discussion created by Thomas Kobler on Oct 22, 2008
Latest reply on Oct 22, 2008 by Ake Webjorn

The documentation on the MC9S08DZ with the TPMV3 is unclear on how to select one of the available channel IO pins instead of the dedicated extern clock pin for the TPM (which is not available in the 32 pin package). It just tells not to use the pin as channel input, of course, but not how to select the pin. All it says is:

"The external clock source may be connected to any TPM channel pin."


"The external clock signal shares the same pin as a channel I/O pin, so the channel pin will not be usable
for channel I/O function when selected as the external clock source. [..] If this pin is used as an external clock source (CLKSB:CLKSA = 1:1), the channel can still be used in output compare mode as a software timer (ELSnB:ELSnA = 0:0)."

The block diagram also doesn't show any MUX or selection mechanism. Neither does the parallel port pin section of port D, where the channel pins are located as alternate function.

Any hints?

Thank you!



Added p/n to subject.

Message Edited by NLFSJ on 2008-10-22 06:48 AM