Portable_Speed2 6 (changes)

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Programmer's Portable Reference Manuals

» Part 15 – SWI Calls

» Portable Portable_Speed2

» Portable_Speed2 6Portable_Speed2

Portable_Speed2 6

(SWI &42FCE)

Use

The purpose of this call is to convert a CPU clock rate from a MHz value to a speed index. If the input value of R1 does not match an available speed, the index of the next lowest available speed will be returned. If R1 is lower than the lowest available speed, 0 (the slowest possible speed) will be returned.

Notes

Due to hardware restrictions or for performance reasons, most systems will only support a limited number of CPU clock rates. This call, along with Portable_Speed2 4 and Portable_Speed2 5 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.

To set the CPU speed, see Portable_Speed2 2 or Portable_Speed2 8 (to set the desired ‘slow’ and ‘fast’ speeds), and Portable_Speed (to switch between the configured ‘slow’ and ‘fast’ speeds).

See also

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