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PIC18F2331 Datasheet, PDF (248/396 Pages) Microchip Technology – 28/40/44-Pin Enhanced Flash Microcontrollers with nanoWatt Technology, High Performance PWM and A/D
PIC18F2331/2431/4331/4431
REGISTER 20-3:
ADCON2 – A/D CONTROL REGISTER 2
R/W-0
ADFM
R/W-0
ACQT3
R/W-0
ACQT2
R/W-0
ACQT1
bit 7
R/W-0
ACQT0
R/W-0 R/W-0
ADCS2 ADCS1
R/W-0
ADCS0
bit 0
bit 7
bit 6-3
bit 2-0
ADFM: A/D Result Format Select bit
1 = Right justified
0 = Left justified
ACQT<3:0>: A/D Acquisition Time Select bits
0000 = No Delay(1) (Conversion starts immediately when GO/DONE is set)
0001 = 2 TAD
0010 = 4 TAD
0011 = 6 TAD
0100 = 8 TAD
0101 = 10 TAD
0110 = 12 TAD
0111 = 16 TAD
1000 = 20 TAD
1001 = 24 TAD
1010 = 28 TAD
1011 = 32 TAD
1100 = 36 TAD
1101 = 40 TAD
1110 = 48 TAD
1111 = 64 TAD
ADCS<2:0>: A/D Conversion Clock Select bits
000 =
001 =
010 =
011 =
100 =
101 =
110 =
111 =
FOSC/2
FOSC/8
FOSC/32
FRC/4(2)
FOSC/4
FOSC/16
FOSC/64
FRC (Internal A/D RC Oscillator)
Note 1: If the A/D clock source is selected as RC, a time of TCY is added before sampling/
conversion starts.
2: Due to an increased frequency of the internal A/D RC oscillator, FRC/4 provides clock
frequencies compatible with previous A/D modules.
3: In sequential mode TACQ should be 12 TAD or greater.
Legend:
R = Readable bit
-n = Value at Reset
W = Writable bit
‘1’ = bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = bit is cleared x = bit is unknown
DS39616B-page 246
Preliminary
 2003 Microchip Technology Inc.