Part Number: TDA4VM
I want to use all channels of ADC0 unit in ti-processor-sdk-rtos-j721e-evm-07_03_00_07.
I configured all the channels in EB.
When my program is running, the voltage from ADC0_AIN7 is abnormal. My input voltage is 0v, but I got a more big value from the converted result.
I removed the input resistor（0Ω）and found that the voltage of ADC0_AIN7 stayed at 1.8v(I/O supply voltage) despite of no input.
Debugging step by step, we found that the voltage changed after the execution of the following statement in function Adc_hwUnitInit() of file Adc_Priv.c:
spareInVal = ((uint32) 1U << ADC_MISC_AFE_SPARE_INPUT_SHIFT);
HW_WR_FIELD32(baseAddr + ADC_MISC, ADC_MISC_AFE_SPARE_INPUT, spareInVal);
1. What does “spare inputs of the AFE” stand for?
2. Why setting AFE_SPARE_IN bit 0 affects ADC0_AIN7 channel?
3. We cannot find detailed information about the four bits AFE_SPARE_IN of register ADC_MISC in TDA4 TRM. What is the relationship between the four bits and ADC channels?
