41.8.3 OPAMP Control x
| Name: | OPAMPCTRLx |
| Offset: | 0x04+4*x, [x=0..2] |
| Reset: | 0x00000080 |
| Property: | PAC Write-Protection |
| Bit | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | |
| Access | |||||||||
| Reset |
| Bit | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | |
| MUXNEG[2:0] | MUXPOS[2:0] | ||||||||
| Access | R/W | R/W | R/W | R/W | R/W | R/W | |||
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | |||
| Bit | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | |
| POTMUX[2:0] | RES1MUX[1:0] | RES1EN | RES2VCC | RES2OUT | |||||
| Access | R/W | R/W | R/W | R/W | R/W | R/W | R/W | R/W | |
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| ONDEMAND | RUNSTDBY | BIAS[1:0] | ANAOUT | ENABLE | |||||
| Access | R/W | R/W | R/W | R/W | R/W | R/W | |||
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | |||
Bits 22:20 – MUXNEG[2:0] Negative Input Mux Selection
Selection on negative input for operational amplifier x.
| Value | OPAMPx | Name | Description |
|---|---|---|---|
| 0x0 | x=0,1,2 | OAxNEG | Negative I/O pin |
| 0x1 | x=0,1,2 | OAxTAP | Resistor ladder x taps |
| 0x2 | x=0,1,2 | OAxOUT | OPAMPx output |
| 0x3 | x=0,1 | DAC | DAC output |
| x=2 | OA0NEG | Negative I/O pin OPA0 | |
| 0x4 | x=0,1 | Reserved | |
| x=2 | OA1NEG | Negative I/O pin OPA1 | |
| 0x5 | x=0,1 | Reserved | |
| x=2 | DAC | DAC output | |
| 0x6 | x=0,1,2 | Reserved | |
| 0x7 | x=0,1,2 | Reserved |
Bits 18:16 – MUXPOS[2:0] Positive Input Mux Selection
Selection on positive input for operational amplifier x.
| Value | OPAMPx | Name | Description |
|---|---|---|---|
| 0x0 | x=0,1,2 | OAxPOS | Positive I/O pin |
| 0x1 | x=0,1,2 | OAxTAP | Resistor ladder x taps |
| 0x2 | x=0 | DAC | DAC output |
| x=1 | OA0OUT | OPAMP0 output | |
| x=2 | OA1OUT | OPAMP1 output | |
| 0x3 | x=0,1,2 | GND | Ground |
| 0x4 | x=0,1 | Reserved | |
| x=2 | OA0POS | Positive I/O pin OPA0 | |
| 0x5 | x=0,1 | Reserved | |
| x=2 | OA1POS | Positive I/O pin OPA1 | |
| 0x6 | x=0,1 | Reserved | |
| x=2 | OA0TAP | Resistor ladder 0 taps | |
| 0x7 | x=0,1,2 | Reserved |
Bits 15:13 – POTMUX[2:0] Potentiometer selection
Resistor selection bits control a numeric potentiometer with eight fixed values.
| Value | R1 | R2 | Gain = R2/R1 |
|---|---|---|---|
| 0x0 | 14R | 2R | 1/7 |
| 0x1 | 12R | 4R | 1/3 |
| 0x2 | 8R | 8R | 1 |
| 0x3 | 6R | 10R | 1 + 2/3 |
| 0x4 | 4R | 12R | 3 |
| 0x5 | 3R | 13R | 4 + 1/3 |
| 0x6 | 2R | 14R | 7 |
| 0x7 | R | 15R | 15 |
Bits 12:11 – RES1MUX[1:0] Resistor 1 Mux
These bits select the connection of R1 resistor of the potentiometer.
| Value | OPAMPx | Name | Description |
|---|---|---|---|
| 0x0 | x=0,1,2 | OAxPOS | Positive inout of OPAMPx |
| 0x1 | x=0,1,2 | OAxNEG | Negative input of OPAMPx |
| 0x2 | x=0 | DAC | DAC output |
| x=1 | OA0OUT | OPAMP0 output | |
| x=2 | OA1OUT | OPAMP1 output | |
| 0x3 | x=0,1,2 | GND |
Bit 10 – RES1EN Resistor 1 Enable
| Value | Description |
|---|---|
| 0 | R1 disconnected from RES1MUX. |
| 1 | R1 connected to RES1MUX. |
Bit 9 – RES2VCC Resistor ladder To VCC
| Value | Description |
|---|---|
| 0 | Swith open. |
| 1 | Switch closed. |
Bit 8 – RES2OUT Resistor ladder To Output
| Value | Description |
|---|---|
| 0 | Swith open. |
| 1 | Switch closed. |
Bit 7 – ONDEMAND On Demand Control
The On Demand operation mode allows the OPAMPx to be enabled or disabled, depending on other peripheral requests.
| Value | Description |
|---|---|
| 0 | The OPAMPx is always on, if enabled. |
| 1 | The OPAMPx is enabled when a peripheral is requesting the OPAMPx to be used as an input. The OPAMPx is disabled if no peripheral is requesting it as an input. |
Bit 6 – RUNSTDBY Run in Standby
This bit controls how the OPAMPx behaves during standby sleep mode:
| Value | Description |
|---|---|
| 0 | The OPAMPx is disabled in standby sleep mode. |
| 1 | The OPAMPx is not stopped in standby sleep mode. If OPAMPCTRLx.ONDEMAND=1, the OPAMPx will be running when a peripheral is requesting it as an input. If OPAMPCTRLx.ONDEMAND=0, OPAMPx will always be running in standby sleep mode. |
Bits 4:3 – BIAS[1:0] Bias Selection
These bits are used to select the bias mode.
| Value | Name | Description |
|---|---|---|
| 0x0 | Mode 0 | Minimum current consumption, but the slowest mode |
| 0x1 | Mode 1 | Low current consumption, slow speed |
| 0x2 | Mode 2 | High current consumption, fast speed |
| 0x3 | Mode 3 | Maximum current consumption but the fastest mode |
Bit 2 – ANAOUT Analog Output
This bit controls a switch connected to the OPAMP output.
| Value | Description |
|---|---|
| 0 | Swith open. No ADC or AC connection. |
| 1 | Switch closed. OPAMP output is connected to the ADC or AC input. |
Bit 1 – ENABLE Operational Amplifier Enable
| Value | Description |
|---|---|
| 0 | The OPAMPx is disabled |
| 1 | The OPAMPx is enabled |