|R0||2 (Reason code)|
|R1||Desired ‘slow’ speed, in MHz|
|R2||Desired ‘fast’ speed, in MHz|
|R1||New ‘slow’ speed, in MHz|
|R2||New ‘fast’ speed, in MHz|
The purpose of this call is to allow the user to select the clock speeds that are associated with Portable_Speeds ‘slow’ and ‘fast’ settings. The values the user supplies in R1 and R2 will be matched to the set of speeds that the hardware supports, and the updated values, representing the new speeds that will actually be used, will be returned to the caller.
Portable_Speed2 8 provides similar functionality to this call, but the speeds are expressed as indices into the list of available speeds, not as raw MHz values.
To read the currently configured ‘slow’ and ‘fast’ speeds, use Portable_Speed2 3.