Microchip Technology DV164136 Data Sheet
2007-2012 Microchip Technology Inc.
DS39778E-page 309
PIC18F87J11 FAMILY
22.0
10-BIT ANALOG-TO-DIGITAL
CONVERTER (A/D) MODULE
CONVERTER (A/D) MODULE
The Analog-to-Digital (A/D) Converter module has
11 inputs for the 64-pin devices and 15 for the 80-pin
devices. This module allows conversion of an analog
input signal to a corresponding 10-bit digital number.
The module has six registers:
• A/D Control Register 0 (ADCON0)
• A/D Control Register 1 (ADCON1)
11 inputs for the 64-pin devices and 15 for the 80-pin
devices. This module allows conversion of an analog
input signal to a corresponding 10-bit digital number.
The module has six registers:
• A/D Control Register 0 (ADCON0)
• A/D Control Register 1 (ADCON1)
• A/D Port Configuration Register 2 (ANCON0)
• A/D Port Configuration Register 1 (ANCON1)
• A/D Result Registers (ADRESH and ADRESL)
The ADCON0 register, shown in
• A/D Port Configuration Register 1 (ANCON1)
• A/D Result Registers (ADRESH and ADRESL)
The ADCON0 register, shown in
, configures
the A/D clock source, programmed acquisition time and
justification.
justification.
REGISTER 22-1:
ADCON0: A/D CONTROL REGISTER 0
(
)
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
VCFG1
VCFG0
CHS3
CHS2
CHS1
CHS0
GO/DONE
ADON
bit 7
bit 0
Legend:
R = Readable bit
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7
VCFG1:
Voltage Reference Configuration bit (V
REF
- source)
1
= V
REF
- (AN2)
0
= AV
SS
bit 6
VCFG0:
Voltage Reference Configuration bit (V
REF
+ source)
1
= V
REF
+ (AN3)
0
= AV
DD
bit 5-2
CHS<3:0>:
Analog Channel Select bits
0000
= Channel 00 (AN0)
0001
= Channel 01 (AN1)
0010
= Channel 02 (AN2)
0011
= Channel 03 (AN3)
0100
= Channel 04 (AN4)
0101
= Unused
0110
= Channel 06 (AN6)
0111
= Channel 07 (AN7)
1000
= Channel 08 (AN8)
1001
= Channel 09 (AN9)
1010
= Channel 10 (AN10)
1011
= Channel 11 (AN11)
1100
= Channel 12 (AN12)
)
1101
= Channel 13 (AN13)
)
1110
= Channel 14 (AN14)
)
1111
= Channel 15 (AN15)
)
bit 1
GO/DONE:
A/D Conversion Status bit
When ADON = 1:
1
1
= A/D conversion is in progress
0
= A/D is Idle
bit 0
ADON:
A/D On bit
1
= A/D Converter module is enabled
0
= A/D Converter module is disabled
Note 1:
Default (legacy) SFR at this address, available when WDTCON<4> = 0.
2:
These channels are not implemented on 64-pin devices.
3:
Performing a conversion on unimplemented channels will return random values.