PIC18F2420/2520/4420/4520
REGISTER 19-2: ADCON1: A/D CONTROL REGISTER 1
U-0
—
U-0
—
R/W-0
R/W-0
R/W-0
R/W-q(1)
PCFG2
R/W-q(1)
PCFG1
R/W-q(1)
PCFG0
VCFG1
VCFG0
PCFG3
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7-6
bit 5
Unimplemented: Read as ‘0’
VCFG1: Voltage Reference Configuration bit (VREF- source)
1= VREF- (AN2)
0= VSS
bit 4
VCFG0: Voltage Reference Configuration bit (VREF+ source)
1= VREF+ (AN3)
0= VDD
bit 3-0
PCFG<3:0>: A/D Port Configuration Control bits:
PCFG3:
PCFG0
0000(1)
0001
0010
0011
0100
0101
0110
A
A
A
D
D
D
D
D
A
A
A
A
D
D
D
D
A
A
A
A
A
D
D
D
A
A
A
A
A
A
D
D
A
A
A
A
A
A
A
D
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
0111(1)
1000
1001
1010
1011
1100
1101
1110
1111
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
A
D
D
D
D
D
D
D
A
A
D
D
D
D
D
D
A
A
A
D
D
D
D
D
A
A
A
A
D
D
D
D
A
A
A
A
A
D
D
D
A
A
A
A
A
A
D
D
A
A
A
A
A
A
A
D
A = Analog input
D = Digital I/O
Note 1: The POR value of the PCFG bits depends on the value of the PBADEN Configuration bit. When
PBADEN = 1, PCFG<2:0> = 000; when PBADEN = 0, PCFG<2:0> = 111.
2: AN5 through AN7 are available only on 40/44-pin devices.
DS39631E-page 224
© 2008 Microchip Technology Inc.