#include <nitro/spi.h>typedef enum
{
MIC_SAMPLING_RATE_8K = ( HW_CPU_CLOCK_ARM7 / 8000 ) ,
MIC_SAMPLING_RATE_11K = ( HW_CPU_CLOCK_ARM7 / 11025 ) ,
MIC_SAMPLING_RATE_16K = ( HW_CPU_CLOCK_ARM7 / 16000 ) ,
MIC_SAMPLING_RATE_22K = ( HW_CPU_CLOCK_ARM7 / 22050 ) ,
MIC_SAMPLING_RATE_32K = ( HW_CPU_CLOCK_ARM7 / 32000 )
MIC_SAMPLING_RATE_LIMIT = 1024
} MICSamplingRate;
This is a list of the sampling rates.
These values define typical sampling rates that are converted into ARM7 timer cycles.
MIC_SAMPLING_RATE_8K |
8 kHz |
MIC_SAMPLING_RATE_11K |
11.025 kHz |
MIC_SAMPLING_RATE_16K |
16 kHz |
MIC_SAMPLING_RATE_22K |
22.05 kHz |
MIC_SAMPLING_RATE_32K |
32 kHz |
MIC_SAMPLING_RATE_LIMIT |
The shortest sampling rate that is supported. |
The ARM7 can support sampling rates up to MIC_SAMPLING_RATE_LIMIT when devoted to microphone sampling, but we cannot guarantee this when the ARM7
is also being used for sounds and other features. Please specify an appropriate
rate, keeping in mind the load placed on the ARM7.
The ARM7 timer is set in units of CPU clock ticks, so appreciate that
error is built into the defined frequencies.
MIC_StartAutoSampling, MIC_StartAutoSamplingAsync
06/01/2004 Initial version