8-bit MicrocontrollersのトピックRe: External Crystal = 32 kHz, Maximum bus Frequency

External Crystal = 32 kHz, Maximum bus Frequency

WillemEradus — Tue, 19 May 2009 23:26:27 GMT

I have an evolution board with a MC9S08LC60 and an external crystal of 32 kHz. In the example, the FLL will be used (in FEE mode) to multiply the external 32 kHz oscillator up to 8.38MHz to achieve 4.19 MHz bus frequency. My question is what is the maximum bus frequency I can achieve with this setup.

Thx, Willem.

Re: External Crystal = 32 kHz, Maximum bus Frequency

peg — Wed, 20 May 2009 05:36:21 GMT

Hello and welcome to the fora, Willem.

In your example the multiplier used is 4.

The maximum multiplier available is 18

4.19 * 18 / 4 = 18.8MHz

Refer to datasheet Chapter 10, ICG for more details .

Re: External Crystal = 32 kHz, Maximum bus Frequency

WillemEradus — Wed, 20 May 2009 12:36:31 GMT

thanks !