Texas Instruments MSP430x4xx - Manual (Page 320)

OA Registers
16-13 OA
OAxCTL1, Opamp Control Register 1
7 6 5 4 3 2 1 0
OAFBRx OAFCx Reserved OARRIP
rw−0 rw−0 rw−0 rw−0 rw−0 rw−0 rw−0 rw−0
OAFBRx Bits
7-5 OAx feedback resistor select
000 Tap 0
001 Tap 1
010 Tap 2
011 Tap 3
100 Tap 4
101 Tap 5
110 Tap 6
111
Tap 7
OAFCx Bits
4-2 OAx function control. This bit selects the function of OAx
000 General purpose
001 Unity gain buffer
010 Reserved
011 Comparing amplifier
100 Non-inverting PGA
101 Reserved
110 Inverting PGA
111
Differential amplifier
Reserved Bit 1 Reserved
OARRIP Bit 0 OA rail-to-rail input off.
0
OAx input signal range is rail-to-rail
1 OAx input signal range is limited. See device datasheet for
parameters.