PROCESSOR-SDK-AM437X: ADC channels configuration

Hello E2E community,

I have a custom board based on AM4377 and ADC input signal are routed according to this schematic;

The problem #1 is that ADC1 isn't working. Looks like it is reserved for security applications and unlocked only on AM437xHS board:

uint32_t CHIPDBIsSecureModule(const chipdbModuleID_t moduleID)
{
    switch (moduleID)
    {
        case CHIPDB_MOD_ID_CRYPTODMA:
        case CHIPDB_MOD_ID_DES:
        case CHIPDB_MOD_ID_SHA:
        case CHIPDB_MOD_ID_AES:
        case CHIPDB_MOD_ID_ADC1: /* <-- why???*/
        case CHIPDB_MOD_ID_RNG:
        case CHIPDB_MOD_ID_PKA:
            return TRUE;
        default:
            return FALSE;
    }

    return FALSE;
}

Any legitimate way to use ADC1 additionally to ADC0 in my application?

The problem #2: how to properly configure the ADC channels?

I take "pdk_am437x_1_0_14\packages\ti\starterware\examples\adc" as an example and extend it to read from all 9 channels: TSCADC_INPUT_CHANNEL1..TSCADC_INPUT_CHANNEL8 + TSCADC_INPUT_VREFN.

I configure every channel like this:

            adcStepCfg.adcNegativeInpRef = TSCADC_NEGATIVE_REF_VSSA;
            adcStepCfg.adcPositiveInpRef = TSCADC_POSITIVE_REF_VDDA;
            adcStepCfg.adcNegativeInpChan = TSCADC_INPUT_CHANNEL1;
            adcStepCfg.adcPositiveInpChan = TSCADC_INPUT_CHANNEL1;
            adcStepCfg.enableXppsw = TRUE;
            adcStepCfg.enableXnpsw = FALSE;
            adcStepCfg.enableYppsw = FALSE;
            adcStepCfg.enableXnnsw = TRUE;
            adcStepCfg.enableYpnsw = FALSE;
            adcStepCfg.enableYnnsw = FALSE;
            adcStepCfg.enableWpnsw = FALSE;
            [. . .]
            adcStepCfg.adcNegativeInpRef = TSCADC_NEGATIVE_REF_VSSA;
            adcStepCfg.adcPositiveInpRef = TSCADC_POSITIVE_REF_VDDA;
            adcStepCfg.adcNegativeInpChan = TSCADC_INPUT_CHANNEL8;
            adcStepCfg.adcPositiveInpChan = TSCADC_INPUT_CHANNEL8;
            adcStepCfg.enableXppsw = TRUE;
            adcStepCfg.enableXnpsw = FALSE;
            adcStepCfg.enableYppsw = FALSE;
            adcStepCfg.enableXnnsw = TRUE;
            adcStepCfg.enableYpnsw = FALSE;
            adcStepCfg.enableYnnsw = FALSE;
            adcStepCfg.enableWpnsw = FALSE;
            [. . .]
            adcStepCfg.adcNegativeInpRef = TSCADC_NEGATIVE_REF_VSSA;
            adcStepCfg.adcPositiveInpRef = TSCADC_POSITIVE_REF_VDDA;
            adcStepCfg.adcNegativeInpChan = TSCADC_INPUT_VREFN;
            adcStepCfg.adcPositiveInpChan = TSCADC_INPUT_VREFN;
            adcStepCfg.enableXppsw = TRUE;
            adcStepCfg.enableXnpsw = FALSE;
            adcStepCfg.enableYppsw = FALSE;
            adcStepCfg.enableXnnsw = TRUE;
            adcStepCfg.enableYpnsw = FALSE;
            adcStepCfg.enableYnnsw = FALSE;
            adcStepCfg.enableWpnsw = FALSE;

But when I do the reading (doesn't matter if I use FIFO#0 or FIFO#1, or both interleaving), I always get the same readings:

ADC0 @ 0x44e0d000
Voltage sensed on the ADC0_AIN0 line :1796mV (4093 counts)
Voltage sensed on the ADC0_AIN1 line :0mV (0 counts)
Voltage sensed on the ADC0_AIN2 line :1658mV (3779 counts)
Voltage sensed on the ADC0_AIN3 line :1448mV (3300 counts)
Voltage sensed on the ADC0_AIN4 line :1247mV (2842 counts)
Voltage sensed on the ADC0_AIN5 line :1222mV (2784 counts)
Voltage sensed on the ADC0_AIN6 line :1199mV (2732 counts)
Voltage sensed on the ADC0_AIN7 line :1197mV (2727 counts)
Voltage sensed on the ADC0_AIN8 line :0mV (0 counts)

Let's put aside conversion to volts, it is not important at the moment although I would like to know how to calculate the multiplier. As I suspect that, according to the first picture, I have to get some readings on the first 3 channels and on the last two. But it is not the case! I think the positive and negative reference points are wrongly set. Can you provide an advice how should I do it correctly? Is there a detailed manual describing what all these parameters in the step configuration mean? All these: .adcNegativeInpRef, .adcPositiveInpRef, .adcNegativeInpChan, .adcPositiveInpChan?

And all of these too: .enableXppsw, .enableXnpsw, ... ????

Thank you very much in advance, your help will be very appreciated!