Carlos dL

Frequency Problem - ICS

Discussion created by Carlos dL on Mar 27, 2012
Latest reply on Mar 28, 2012 by Carlos dL


I was trying to configure the SCI module of my MC9S08SH and I make a very simple code, it just send a "2" by the TxD.

But it never works, so I start to look for the problem in RS232 circuit and in the PC but nothing. So I doubt about the frequency clock, because I supposed that it was 8 Mhz just because I read an example, but reading different articles I discover the ICS register.And now I am thinking that the problem is there, because the configured frequency is not the one I thought.

My debbuger is an OSBDM and CW 10.1. I read that "during the flash programming process, the internal reference needs to be calibrated for a frequency of 39.0625 kHz.  This is the "non-volatile (NV) trim", and is programmed to a specific flash memory location"

A really do not know how to calibrate the bus frequency, Which register I must load to have a 39.0625kHz frequency? How to do it?

If somebody could help me to know which is the bus frequency , and how it works and can be calibrated I will be very grateful.

Thanks very much for your help in advance.


PD: Sorry for my english is not my native language.