Datasheet

 2003-2013 Microchip Technology Inc. DS39609C-page 213
PIC18F6520/8520/6620/8620/6720/8720
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.
The module has five registers:
• 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 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
— — CHS3 CHS2 CHS1 CHS0 GO/DONE ADON
bit 7 bit 0
bit 7-6 Unimplemented: Read as ‘0’
bit 5-2 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)
1100 = Channel 12 (AN12)
(1)
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 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
bit 0 ADON: A/D On bit
1 = A/D converter module is enabled
0 = A/D converter module is disabled
Legend:
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