68300

Hello list,

I am using 68332 TPU UART function and having the problem to use it
with slow baud, say less than 100 bps. The UART function seems not
working well with any speed lower than 200 for TPU clock of
16777000 / 4. If I slow down the TPU clock to 16777000 / 32, it works
with 100bps.

The UART document only mentioned the upper limit of the speed, but
does not tell what is the slowest speed it can be used.

To solve the problem, I tried to switch the clock to lower speed when
I used it for slow baud and changed it back after the task was done.
However, I got a problem that the TCR1P and PSCK fields in TPUMCR
register can only be written once after the reset, hence prevents
from dynamically changing the TPU clock.

It would be very helpful if anybody can provide answers to the
following questions:
1) What is the low speed limit of UART function?
2) How to (or is it possible) to change TPU clock dynamically without
resetting 68332?

Any advice will be mostly welcome.

Thanks in advance.

John