MSCAN on HCS12

[Saud]

i wanted to know what is bus clock ?,is it different from the internal oscillator clock.

also what is  Oscillator Clock for MC9s12C32  16MHz or 25Mhz .i want to use Mscan can Module at 1Mbps data rate.

which clock (oscillator or Bus ) should i select and why?

[Steve]

Saud,

  The bus clock is the operating clock for the MCU. This can be from the oscillator or from the PLL.

   Unfortunately, CAN is not as simple as the SCI and so there is no simple spec on how to get a 1Mbps clock. The bus speed depends on the number of time quanta in a bit and that is totally dependent on your CAN bus architecture. As you read through the CAN module description you will find calculations for the bit time and the bus speed based on the bus configuration. The choice of clock source is also discussed in there.