PIC18F87J90 Datasheet, PDF (289/450 Pages) Microchip Technology – 64/80-Pin, High-Performance Microcontrollers with LCD Driver and nanoWatt Technology

PIC18F87J90 FAMILY
21.0 10-BIT ANALOG-TO-DIGITAL
CONVERTER (A/D) MODULE
The Analog-to-Digital (A/D) Converter module has
12 inputs for all PIC18F87J90 family 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 21-1,
controls the operation of the A/D module. The
ADCON1 register, shown in Register 21-2, configures
the functions of the port pins. The ADCON2 register,
shown in Register 21-3, configures the A/D clock
source, programmed acquisition time and justification.
REGISTER 21-1: ADCON0: A/D CONTROL REGISTER 0
R/W-0
U-0
ADCAL
—
bit 7
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 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
bit 6
bit 5-2
bit 1
bit 0
ADCAL: A/D Calibration bit
1 = Calibration is performed on next A/D conversion
0 = Normal A/D Converter operation (no calibration is performed)
Unimplemented: Read as ‘0’
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 = Channel 05 (AN5)
0110 = Channel 06 (AN6)
0111 = Channel 07 (AN7)
1000 = Channel 08 (AN8)
1001 = Channel 09 (AN9)
1010 = Channel 10 (AN10)
1011 = Channel 11 (AN11)
11xx = Unused
GO/DONE: A/D Conversion Status bit
When ADON = 1:
1 = A/D conversion in progress
0 = A/D Idle
ADON: A/D On bit
1 = A/D Converter module is enabled
0 = A/D Converter module is disabled
 2010 Microchip Technology Inc.
DS39933D-page 289