Using extern 5MHz clock, set bus to 10MHz, When I use RDIV other than divide 128, MCU work the same.
Strange, is it?
Normally the device after reset set the ICS to use the internal clock, (FEI), so probably your device is running with the internal clock, you can check it debuging the ICS register using code warrior.
Are you sure that the MCU is running with the external clock?
Not quite sure. Just find serial communication still working.
UM doesn't mention what happens when a abnormal value is used.
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