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for ARM devices
Portable_Speed
Programmer's Reference Manuals
» Part 15 – SWI Calls
» Portable
» Portable_Speed
Portable_Speed
(SWI &42FC0)
| Entry | |
|---|---|
| R0 | EOR mask |
| R1 | AND mask |
| Exit | |
|---|---|
| R0 | Old speed value |
| R1 | New speed value |
Use
The purpose of this call is to set the processor speed.
Notes
The new speed is set as:
New value = (old speed AND R2) EOR R1
Currently supported speed settings are:
| 0 | Fast |
| 1 | Slow |
Some hardware allows programs to exert more control over the CPU speed by SWI Portable_Speed2 to specify what clock rates the ‘slow’ and ‘fast’ speed settings equate to.