AT89LP51RB2_14 Datasheet, PDF (163/254 Pages) ATMEL Corporation – 8-bit Microcontroller Compatible with 8051 Products

AT89LP51RB2/RC2/IC2 Preliminary
Table 20-3. AREF – Analog Comparator Reference Control Register
AREF = BDH
Not Bit Addressable
CMPB
CMPA
RFB1
RFB0
CCS1
Bit
7
6
5
4
3
Symbol Function
CMPB
Comparator B Output.
Copy of Comparator B raw output value sampled by the system clock.
CMPA
RFB_1-0
Comparator A Output
Copy of Comparator A raw output value sampled by the system clock.
Comparator B Negative Input Channel Select⁽¹⁾
CRF1 RFB0 B- Channel
0
0
AIN2 (P2.6)
CCS_1-0
0
0
Internal V_AREF-Δ (~1.125V)
0
1
Internal V_AREF (~1.25V)
0
1
Internal V_AREF+Δ (~1.375V)
Comparator Clock Select
CCS1 CCS0 Clock Source
0
0
System Clock
0
0
Timer 0 Overflow
0
1
Timer 1 Overflow
0
1
Timer 2 Overflow
RFA_1-0
Comparator A Negative Input Channel Select⁽²⁾
RFA1 RFA0 A- Channel
0
0
AIN1 (P2.5)
Notes:
0
0
Internal V_AREF-Δ (~1.125V)
0
1
Internal V_AREF (~1.25V)
0
1
Internal V_AREF+Δ (~1.375V)
1. CONB (ACSRB.5) must be cleared to 0 before changing RFB[1-0].
2. CONA (ACSRA.5) must be cleared to 0 before changing RFA[1-0].
Reset Value = 0000 0000B
CCS0
2
RFA1
1
RFA0
0
3722A–MICRO–10/11
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