[ts-7000] TS-ADC24 max sample rate?

["bburtan65" <>]

Okay, so Technologic states several times in the literature for the ADC24 board 
that it has a 1Msps sample rate.  However, in my experience so far just 
sampling the minimum four channels, the absolute best I seem to be able to do 
is 100ksps before the buffer overflows and the ADC stops.

Here is a code snippet:

adc = (ADC_Data_Type *)mmap(0, getpagesize(), PROT_READ|PROT_WRITE, MAP_SHARED, 
fd, IO_BASE);
adc += (ADC_OFFSET)/sizeof(ADC_Data_Type);
adc_channel_address = adc + 0x4;        // For slightly faster access to the 
channel register
adc_data_address = adc + 0x5;           // For slightly faster access to the 
sample data

ADC(2) = 0;             // Reset the ADC
configuration = configuration | diff_mode;
if (diff_mode == kDiff_Mode_Single_Ended)
        configuration = configuration | kDiff_Mode_Single_Ended_8bit;
configuration = configuration | input_range;
configuration = configuration | ((num_channel_blocks-1) << 1);
num_channels = num_channel_blocks * 4;
ADC(2) = configuration | 1;



The main loop is here:

do {
        current_channel = ((*(adc_channel_address)) >> 1) & 0x1f;
        sample_data = (*(adc_data_address));
} while (current_channel != 0);
                
adcValue = (sample_data & 0x07ff) + (!(sample_data & 0x800)*0x800);


If I do nothing else but the above do/while and adcValue lines, 100ksps is 
about the maximum.  If I'm running other threads that slows way down.  So why 
can I never get 1Msps?




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