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PIC16F87X Datasheet, PDF (114/218 Pages) Microchip Technology – 28/40-pin 8-Bit CMOS FLASH Microcontrollers
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PIC16F87X
REGISTER 11-2: ADCON1 REGISTER (ADDRESS 9Fh)
U-0
U-0
R/W-0
U-0
ADFM
—
—
—
bit 7
R/W-0
PCFG3
R/W-0
PCFG2
R/W-0
PCFG1
R/W-0
PCFG0
bit 0
bit 7
bit 6-4
bit 3-0
ADFM: A/D Result Format Select bit
1 = Right justified. 6 Most Significant bits of ADRESH are read as ‘0’.
0 = Left justified. 6 Least Significant bits of ADRESL are read as ‘0’.
Unimplemented: Read as '0'
PCFG3:PCFG0: A/D Port Configuration Control bits:
PCFG3: AN7(1) AN6(1) AN5(1)
PCFG0 RE2 RE1 RE0
0000
A
A
A
0001
A
A
A
0010
D
D
D
0011
D
D
D
0100
D
D
D
0101
D
D
D
011x
D
D
D
1000
A
A
A
1001
D
D
A
1010
D
D
A
1011
D
D
A
1100
D
D
D
1101
D
D
D
1110
D
D
D
1111
D
D
D
A = Analog input D = Digital I/O
AN4
RA5
A
A
A
A
D
D
D
A
A
A
A
A
D
D
D
AN3
RA3
A
VREF+
A
VREF+
A
VREF+
D
VREF+
A
VREF+
VREF+
VREF+
VREF+
D
VREF+
AN2
RA2
A
A
A
A
D
D
D
VREF-
A
A
VREF-
VREF-
VREF-
D
VREF-
AN1
RA1
A
A
A
A
A
A
D
A
A
A
A
A
A
D
D
AN0
RA0
A
A
A
A
A
A
D
A
A
A
A
A
A
A
A
VREF+
VDD
RA3
VDD
RA3
VDD
RA3
VDD
RA3
VDD
RA3
RA3
RA3
RA3
VDD
RA3
VREF-
VSS
VSS
VSS
VSS
VSS
VSS
VSS
RA2
VSS
VSS
RA2
RA2
RA2
VSS
RA2
CHAN/
Refs(2)
8/0
7/1
5/0
4/1
3/0
2/1
0/0
6/2
6/0
5/1
4/2
3/2
2/2
1/0
1/2
Note 1: These channels are not available on PIC16F873/876 devices.
2: This column indicates the number of analog channels available as A/D inputs and
the number of analog channels used as voltage reference inputs.
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
The ADRESH:ADRESL registers contain the 10-bit
result of the A/D conversion. When the A/D conversion
is complete, the result is loaded into this A/D result reg-
ister pair, the GO/DONE bit (ADCON0<2>) is cleared
and the A/D interrupt flag bit ADIF is set. The block dia-
gram of the A/D module is shown in Figure 11-1.
After the A/D module has been configured as desired,
the selected channel must be acquired before the con-
version is started. The analog input channels must
have their corresponding TRIS bits selected as inputs.
To determine sample time, see Section 11.1. After this
acquisition time has elapsed, the A/D conversion can
be started.
DS30292C-page 112
 2001 Microchip Technology Inc.
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