I am using a S9KEAZN64AMLC controller with a 5.3V power supply. I have a scope on the power supply and see that it is stable.
I have the PIT triggering ADC conversions at 500us.
The ADC is configured to take 4 12 bit readings with 16 bit right justified results.
The ADC is configured as
- Discontinuous mode OFF, Low power mode OFF, ADC clock 1Mhz, Conversion time 40us, Sample time 23.5 clock periods.
- When I read the bandgap and dump the results to a serial port, I see the 8 LSB's changing, corresponding to about 1.11 to 1.21V
- The CPU is clocked at 8Mhz (both Core and Bus)
I was hoping that the values will have good precision and maintain at least 4LSB's.
Could you tell me what I am doing wrongly and what I may try?