Thomas Gaffney

What is bus clock rate on S12X?

Discussion created by Thomas Gaffney on Aug 1, 2006
Latest reply on Aug 9, 2006 by Daniel Malik
I am using a MC9S12XDP512 on a target board with a 20 MHz oscillator being used as an input on the EXTAL pin.  I am then assuming that I have a Bus Clock of 10 MHz (because of the divide by 2 mechanism in the System Clocks Generator figure of the S12X manual).
 
I do not think I am getting a 10 MHz clock for my Bus Clock because I tried using the MSCAN module and to synchronize it with an external tester, I had to configure the MSCAN as though it had a 1.5 MHz input clock which did not make sense.
 
I am doing no configuration on the PLL or the CRG.  My question is, what should the bus clock frequency be in my example and what, if any, configuration of registers do I need to do on the CRG.
 
Thank you,
 
Thomas Gaffney

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