8-bit MicrocontrollersのトピックRe: Timer Information required for MC13192

Timer Information required for MC13192

mou — Wed, 22 Aug 2007 16:42:41 GMT

In the MC13192Reference Manual, available at www.freescale.com, the timer information says that registers 0x1D and 0x1E hold the future time. Register 0x1D hold the most significant bits and 0x1E hold the least significant bits.I have set the the values of 0x1D and 0x1E to 0x0000 and 0x0002. Again, registers 0x26 and 0x27 hold the current time.I have set the values of 0x26 and 0x27 to 0x0000 and 0x0000. Can anyone tell me exactly how much time difference(in secs/msecs) will be there between current time and future time?

Re: Timer Information required for MC13192

UK_CF_FAE — Fri, 31 Aug 2007 21:38:54 GMT

Hi Mou,

Sorry that your post has gone unanswered for a week.

The MC1319x contains a timer block, clocked from the 16MHz crystal. There is a prescaler for the timer found in register 0x09. This defaults to a timer clock of 250kHz. The current counter value is in registers 27 and 28, and the timebase for this is the output of the presclaer block. Assuming the default 250kHz, this gives a timer quantization of 4us, so each increment of the timer is 4 us. Your programming below will cause a timer event in 8 useconds.

Hope that helps

Mark