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Diffstat (limited to 'doc/README.MPC866')
| -rw-r--r-- | doc/README.MPC866 | 24 |
1 files changed, 0 insertions, 24 deletions
diff --git a/doc/README.MPC866 b/doc/README.MPC866 deleted file mode 100644 index 4707cb7..0000000 --- a/doc/README.MPC866 +++ /dev/null @@ -1,24 +0,0 @@ -The current implementation allows the user to specify the desired CPU -clock value, in MHz, via an environment variable "cpuclk". - -Four compile-time constants are used: - - CONFIG_8xx_OSCLK - input quartz clock - CONFIG_SYS_8xx_CPUCLK_MIN - minimum allowed CPU clock - CONFIG_SYS_8xx_CPUCLK_MAX - maximum allowed CPU clock - CONFIG_8xx_CPUCLK_DEFAULT - default CPU clock value - -If the "cpuclk" environment variable value is within the CPUCLK_MIN / -CPUCLK_MAX limits, the specified value is used. Otherwise, the -default CPU clock value is set. - -Please make sure you understand what you are doing, and understand -the restrictions of your hardware (board, processor). For example, -ethernet will stop working for CPU clock frequencies below 25 MHz. - -Please note that the new clock-handling code is enabled if -CONFIG_8xx_CPUCLK_DEFAULT is defined. Since this mechanism supports -only MPC866 and newer CPUs, this constant MUST NOT be defined for -MPC823/850/860/862 series. The clock generation algorithm for older -chips is different and has not been implemented yet. If you need it, -your patch is welcome. |