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Function RTMPBusFromCPUClock

RTMPBusFromCPUClock measures the external bus clock of the CPU using the internal CPU clock:

UINT RTMPBusFromCPUClock(UINT CPUClockMhz, UINT MeasureClocks);

Parameters

CPUClockMhz

The CPU's internal clock in MHz. Systems with an System Management BIOS can use function RTSMBIOSGetCPUSpeed to query this value.

MeasureClocks

Number of CPU clock cycles to use for the measurement. Larger values improve the accuracy, but take more time. A value such as 40000000 (about 1/100th of a second on a 4GHz CPU) should return results with less than 1% error.

return value

The measured bus clock or 0 on failure.

The function requires APIC mode and will call RTMPSetAPICMode(0) if in PIC mode. It reprograms the APIC timer, so the APIC timer on the local CPU should not be in use through RTMPInitAPICTimer.

Function RTMPInitAPICTimer

Function RTMPDumpInfo