doc/README.MPC866

   1 The current implementation allows the user to specify the desired CPU
   2 clock value, in MHz, via an environment variable "cpuclk".
   3
   4 Three compile-time constants are used:
   5
   6         CFG_866_OSCCLK            - input quartz clock
   7         CFG_866_CPUCLK_MIN        - minimum allowed CPU clock
   8         CFG_866_CPUCLK_MAX        - maximum allowed CPU clock
   9         CFG_866_CPUCLK_DEFAULT    - default CPU clock value
  10
  11 If the "cpuclk" environment variable value is within the CPUCLK_MIN /
  12 CPUCLK_MAX limits, the specified value is used. Otherwise, the
  13 default CPU clock value is set.
  14
  15 Please note that for now the new clock-handling code has been enabled
  16 for the TQM866M board only, even though it should be pretty much
  17 common for other MPC859 / MPC866 based boards also. Our intention
  18 here was to move in small steps and not to break the existing code
  19 for other boards.