TM4C1231D5PZ: Multiple ADC sequences over both ADCs at the same time

Hi,

  I'm not too sure why you would measure 0 on channel 10, 11 and 20. Can you do three experiments?

  1. Turn off ADC0. Only use ADC1 to measure 8-11 + 20. Will you get correct reading for 10, 11 and 20?

  2. Turn off ADC0. Only use ADC1 to measure three channels for 10, 11 and 20? What is the result. 

  3. Use ADC0 for only 8 - 11 + 20. What is the result?

Thanks for the quick reply.

1. Doing so gives me the same output. Channel 10, 11 and 20 remain 0 while 8 and 9 have readouts.

2. Using only channel 10, 11 and 20 gives me the read from 10 and 11

3. Swapping ADC1 for ADC0, gives me correct readouts of the channels

Hi Ayrton,

  Thank you for gather these data points. 

  - Can you please share your code?

  - How do you configure the clock? I want to know if it is related to the below errata. 

  - Do you have another board that you can replicate the same problem?

  Sorry, can you try two more experiments as I have never come across a problem reporting as such?

  - Turn off ADC0 and only use ADC1. Use ADC1 to sample in this order 10, 11, 20, 8, 9 instead of 8, 9, 10, 11, 20. Will you still see 10, 11, 20 equal to 0 while 8 and 9 are sampled correctly?

  - Turn off ADC0 and only use ADC1. Use ADC1 to sample   10, 11, 20 in one sequencer (e.g. SS0) while sampling 8, 9 on another sequencer (eg. SS1) .  Will you still see 10, 11, 20 equal to 0 while 8 and 9 are sampled correctly?

Hi

I added below code. This is only the ADC part of the code. 

#define MAX_ADC0_CHANNELS       8
#define MAX_ADC1_CHANNELS       5

#define ADC_5V                  ADC_CTL_CH0
#define ADC_3V3                 ADC_CTL_CH1
#define ADC_2V5                 ADC_CTL_CH2
#define ADC_1V8                 ADC_CTL_CH3
#define ADC_1V5                 ADC_CTL_CH4
#define ADC_1V2                 ADC_CTL_CH5
#define ADC_1V1                 ADC_CTL_CH6
#define ADC_3V3A                ADC_CTL_CH7
#define ADC_12V                 ADC_CTL_CH8
#define ADC_1V8A                ADC_CTL_CH9
#define ADC_n5V                 ADC_CTL_CH10
#define ADC_1V                  ADC_CTL_CH11
#define ADC_1V8B                ADC_CTL_CH20

struct adc_channel {
    uint32_t channel;
    int nominal_voltage_d;
    int nominal_voltage_a;
    int min_voltage;
    int max_voltage;
};

enum adc0_index {
    _5V,
    _1V,
    _1V8,
    _1V5,
    _1V2,
    _3V3,
    _2V5,
    _1V1
};

enum adc1_index {
    _3V3A,
    _12V,
    _1V8A,
    _n5V,
    _1V8B
};

const struct adc_channel adc0[] = {
    {ADC_5V,    _5V_DIGITAL,    _5V_ANALOG,        _5V_DIGITAL - _5V_DIFF,          _5V_DIGITAL + _5V_DIFF},
    {ADC_1V,    _1V_DIGITAL,    _1V_ANALOG,        _1V_DIGITAL - _1V_DIFF,          _1V_DIGITAL + _1V_DIFF},
    {ADC_1V8,   _1V8_DIGITAL,   _1V8_ANALOG,       _1V8_DIGITAL - _1V8_DIFF,        _1V8_DIGITAL + _1V8_DIFF},
    {ADC_1V5,   _1V5_DIGITAL,   _1V5_ANALOG,       _1V5_DIGITAL - _1V5_DIFF,        _1V5_DIGITAL + _1V5_DIFF},
    {ADC_1V2,   _1V2_DIGITAL,   _1V2_ANALOG,       _1V2_DIGITAL - _1V2_DIFF,        _1V2_DIGITAL + _1V2_DIFF},
    {ADC_3V3,   _3V3_DIGITAL,   _3V3_ANALOG,       _3V3_DIGITAL - _3V3_DIFF,        _3V3_DIGITAL + _3V3_DIFF},
    {ADC_2V5,   _2V5_DIGITAL,   _2V5_ANALOG,       _2V5_DIGITAL - _2V5_DIFF,        _2V5_DIGITAL + _2V5_DIFF},
    {ADC_1V1,   _1V1_DIGITAL,   _1V1_ANALOG,       _1V1_DIGITAL - _1V1_DIFF,        _1V1_DIGITAL + _1V1_DIFF},
};

const struct adc_channel adc1[] = {
   {ADC_3V3A,   _3V3A_DIGITAL,  _3V3A_ANALOG,      _3V3A_DIGITAL - _3V3A_DIFF,      _3V3A_DIGITAL + _3V3A_DIFF},
   {ADC_12V,    _12V_DIGITAL,   _12V_ANALOG,       _12V_DIGITAL - _12V_DIFF,        _12V_DIGITAL + _12V_DIFF},
   {ADC_1V8A,   _1V8A_DIGITAL,  _1V8A_ANALOG,      _1V8A_DIGITAL - _1V8A_DIFF,      _1V8A_DIGITAL + _1V8A_DIFF},
   {ADC_n5V,    _n5V_DIGITAL,   _n5V_ANALOG,       _n5V_DIGITAL - _n5V_DIFF,        _n5V_DIGITAL + _n5V_DIFF},
   {ADC_1V8B,   _1V8B_DIGITAL,  _1V8B_ANALOG,      _1V8B_DIGITAL - _1V8B_DIFF,      _1V8B_DIGITAL + _1V8B_DIFF},
};

void irq_handler()
{
	//handle IRQ
}

int setup_adc_sequence0(uint32_t adc_base,const struct adc_channel * adc_channels, int channels)
{
    int i = 0;

    ADCClockConfigSet(adc_base, ADC_CLOCK_SRC_PIOSC | ADC_CLOCK_RATE_EIGHTH, 1);

    for(i = 0; i < channels; i++) {
        if(i != channels - 1)
            ADCSequenceStepConfigure(adc_base, 0, i,  adc_channels[i].channel);
        else
            ADCSequenceStepConfigure(adc_base, 0, i,  adc_channels[i].channel | ADC_CTL_IE | ADC_CTL_END);
    }

    ADCSequenceConfigure(adc_base, 0, ADC_TRIGGER ALWAYS, 3);

    ADCIntClear(adc_base, 0);
	ADCSequenceEnable(adc_base, 0);

    ADCIntRegister(adc_base, sequence, irq_handler);
	ADCIntEnable(adc_base, 0);

    return 0;
}

int setup_adc()
{
    int i = 0;

    SysCtlPeripheralEnable(SYSCTL_PERIPH_ADC0);
    SysCtlPeripheralEnable(SYSCTL_PERIPH_ADC1);

    ADCReferenceSet(ADC0_BASE, ADC_REF_INT);
    ADCReferenceSet(ADC1_BASE, ADC_REF_INT);

    for(i = 0; i <= 5; i++)
        GPIOPinTypeADC(GPIO_PORTE_BASE, 0x01 << i);

    for(i = 4; i <= 7; i++)
        GPIOPinTypeADC(GPIO_PORTD_BASE, 0x01 << i);

    GPIOPinTypeADC(GPIO_PORTB_BASE, GPIO_PIN_4);
    GPIOPinTypeADC(GPIO_PORTB_BASE, GPIO_PIN_5);
    GPIOPinTypeADC(GPIO_PORTE_BASE, GPIO_PIN_7);

    setup_adc_sequence0(ADC0_BASE, adc0, MAX_ADC0_CHANNELS);
    setup_adc_sequence0(ADC1_BASE, adc1, MAX_ADC1_CHANNELS);

    return 0;
}

int main(void)
{
    SysCtlClockSet(SYSCTL_SYSDIV_2_5|SYSCTL_USE_PLL|SYSCTL_OSC_MAIN|SYSCTL_OSC_INT);

    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOB);
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOC);
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOE);
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOF);
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOG);
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOJ);
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOK);
	
    SysCtlPeripheralSleepEnable(SYSCTL_PERIPH_ADC0);
    SysCtlPeripheralSleepEnable(SYSCTL_PERIPH_ADC1);
	
	setup_adc();
	
	//do other stuff
	
	return 0;
}

Clock configuration is done in the code above.
For the main clock I use  SysCtlClockSet(SYSCTL_SYSDIV_2_5|SYSCTL_USE_PLL|SYSCTL_OSC_MAIN|SYSCTL_OSC_INT); and the ADC is set with ADCClockConfigSet(adc_base, ADC_CLOCK_SRC_PIOSC | ADC_CLOCK_RATE_EIGHTH, 1);

Tried it with already 3 boards all using TM4C1231D5PZ. All encounter the same issue.

1. In this case, 10 and 11 are read correclty. the others are not.
2. This I will have to try, I come on this when I have