PIC18FXX20
The module has five registers:
19.0 10-BIT ANALOG-TO-DIGITAL
CONVERTER (A/D) MODULE
The analog-to-digital (A/D) converter module has 12
inputs for the PIC18F6X20 devices and 16 for the
PIC18F8X20 devices. This module allows conversion
of an analog input signal to a corresponding 10-bit
digital number.
• A/D Result High Register (ADRESH)
• A/D Result Low Register (ADRESL)
• A/D Control Register 0 (ADCON0)
• A/D Control Register 1 ((ADCON1)
• A/D Control Register 2 ((ADCON2)
The ADCON0 register, shown in Register 19-1, con-
trols the operation of the A/D module. The ADCON1
register, shown in Register 19-2, configures the func-
tions of the port pins. The ADCON2 register, shown in
Register 19-3, configures the A/D clock source and
justification.
REGISTER 19-1: ADCON0 REGISTER
U-0
—
U-0
—
R/W-0
CHS3
R/W-0
CHS2
R/W-0
CHS1
R/W-0
CHS0
R/W-0
GO/DONE
R/W-0
ADON
bit 7
bit 0
bit 7-6
bit 5-2
Unimplemented: Read as '0'
CHS3:CHS0: Analog Channel Select bits
0000= Channel 0 (AN0)
0001= Channel 1 (AN1)
0010= Channel 2 (AN2)
0011= Channel 3 (AN3)
0100= Channel 4 (AN4)
0101= Channel 5 (AN5)
0110= Channel 6 (AN6)
0111= Channel 7 (AN7)
1000= Channel 8 (AN8)
1001= Channel 9 (AN9)
1010= Channel 10 (AN10)
1011= Channel 11 (AN11)(1)
1100= Channel 12 (AN12)
1101= Channel 13 (AN13)(1)
1110= Channel 14 (AN14)(1)
1111= Channel 15 (AN15)(1)
Note 1: These channels are not available on the PIC18F6X20 (64-pin) devices.
bit 1
bit 0
GO/DONE: A/D Conversion Status bit
When ADON = 1:
1= A/D conversion in progress (setting this bit starts the A/D conversion, which is automatically
cleared by hardware when the A/D conversion is complete)
0= A/D conversion not in progress
ADON: A/D On bit
1= A/D converter module is enabled
0= A/D converter module is disabled
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
2003 Microchip Technology Inc.
Advance Information
DS39609A-page 213
MICROCHIP [ MICROCHIP ]
