31.5.3 ADCON2
Note:
- To correctly calculate an average, the number of samples (set in ADRPT) must be 2CRS.
- CRS =
‘b111and‘b000are reserved. - This bit is cleared by hardware when the accumulator operation is complete; depending on oscillator selections, the delay may be many instructions.
- See the “Computation Operation” section for full mode descriptions.
| Name: | ADCON2 |
| Address: | 0x1D28 |
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| PSIS | CRS[2:0] | ACLR | MD[2:0] | ||||||
| Access | R/W | R/W | R/W | R/W | R/W/HC | R/W | R/W | R/W | |
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
Bit 7 – PSIS ADC Previous Sample Input Select
| Value | Description |
|---|---|
| 1 | ADFLTR is transferred to ADPREV at the start of conversion |
| 0 | ADRES is transferred to ADPREV at the start of conversion |
Bits 6:4 – CRS[2:0] ADC Accumulated Calculation Right Shift Select
| Value | Name | Description |
|---|---|---|
| 1 to 6 | MD = ‘b100 |
Low-pass filter time constant is 2CRS, filter gain is 1:1(2) |
| 1 to 6 | MD = ‘b011 to ‘b001 |
The accumulated value is right-shifted by CRS (divided by 2CRS)(1,2) |
| x | MD = ‘b000 or ‘b111 |
These bits are ignored |
Bit 3 – ACLR A/D Accumulator Clear Command(3)
| Value | Description |
|---|---|
| 1 | Registers ADACC and ADCNT and the AOV bit are cleared |
| 0 | Clearing action is complete (or not started) |
Bits 2:0 – MD[2:0] ADC Operating Mode Selection(4)
| Value | Description |
|---|---|
| 111-101 | Reserved |
| 100 | Low-Pass Filter mode |
| 011 | Burst Average mode |
| 010 | Average mode |
| 001 | Accumulate mode |
| 000 | Basic (Legacy) mode |