Portable_Speed2 7 (changes)

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Programmer's Portable Reference Manuals

» Part 15 – SWI Calls

» Portable Portable_Speed2

» Portable_Speed2 7Portable_Speed2

Portable_Speed2 7

(SWI &42FCE)

Use

The purpose of this call is to read the current CPU speed, as an index into the list of available speeds. To instead read the CPU speed as a MHz value, use Portable_Speed2 0.

Notes

Due to hardware restrictions or for performance reasons, most systems will only support a limited number of CPU clock rates. Portable_Speed2 4, Portable_Speed2 5, and Portable_Speed2 6 allow the user to enumerate the list of available clock rates. Index 0 is always the slowest available speed, and (return value of Portable_Speed2 4)-1 is always the highest available speed.

There is no direct method available to set the CPU speed to a desired value. Instead programs must use Portable_Speed2 2 (or Portable_Speed2 8) to set the desired ‘slow’ and ‘fast’ speeds, and then Portable_Speed to switch to the desired speed.

See also

• Portable SWI Calls
• Portable_Speed
• Portable_Speed2
• Portable_Speed2 0
• Portable_Speed2 2
• Portable_Speed2 4
• Portable_Speed2 5
• Portable_Speed2 6
• Portable_Speed2 8