Chris Rogan

ICS Settings for MCF51QE128

Discussion created by Chris Rogan on Feb 9, 2009
Latest reply on May 18, 2010 by Gennadiy Lutayenko
Question about the MCF51QE128 clock module (using DEMOQE board):
I have my board configured to run off the external 32kHz crystal, and have set the following registers
  ICSC1  = 0x00;
  ICSC2  = 0x30;
  ICSSC  = 0x60;
According to the documentation, my bus speed should be 39.85Mhz, but on the Command window of the debugger I get
Frequency change to ~19029757hz.

Which is correct? Also, what is the highest bus speed I can run at (using external crystal) and still get a standard RS232 baud rate?