Jerauld Numata

MC9S08AW32 Clock Generator with 16MHz Osc

Discussion created by Jerauld Numata on Apr 7, 2009
Latest reply on Apr 8, 2009 by Jerauld Numata

I am trying to use a 16 Mhz external oscillator for both the CPU clk and the BUSCLK, but am having difficulty in getting it to operate correctly.  The reason for wanting to use the external oscillator is so that no trimming of the internal clock would be required.

 

Using the internal clock, some chips exhibit baud rate errors without trimming.  I tried to use the initializer, to use the FBE mode, but the debug module fails displaying "frequency change to ~0 hz, repeatedly.

 

The setting from the initializer that works is

ICGC1 = 0x46

ICGC2 = 0x00

 

The setting that I tried to change to is

ICGC1 = 0x52

ICGC2 = OX03

 

Any suggestions?

 

Thanks,

Jerry

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