Jalen Zhang

Question about MC9S08EL32 ICS Trim

Discussion created by Jalen Zhang on Jun 14, 2011
Latest reply on May 31, 2012 by Brax02

Hi, all:

    In the datasheet of MC9S08EL32, charpter 8.4.5 said: " All MCU devices are factory programmed with a trim value in a reserved memory location. This value can be copied to the ICSTRM register during reset initialization. The factory trim value does not include the FTRIM bit. For finer precision, the user can trim the internal oscillator in the application and set the FTRIM bit accordingly".

  My question: I read the reserved memory location 0xFFAF and 0xFFAE, the ruturn value is 0xFF, is this the trim value?

  I tested the busclk using  code: for(:smileywink:{PTBD6=0;PTBD6=1;}, what I get is 17.784Mhz!!! But my system's busclk setting is 16MHz, seems this chip is not trimed.