PIC18F8723 Datasheet, PDF (31/60 Pages) Microchip Technology – 64/80-Pin, 1-Mbit,Enhanced Flash Microcontrollers with 12-Bit A/D and nanoWatt Technology

PIC18F8723 FAMILY
2.0 12-BIT ANALOG-TO-DIGITAL
CONVERTER (A/D) MODULE
The Analog-to-Digital (A/D) Converter module has
12 inputs for the 64-pin devices (PIC18F6628/6723) and
16 for the 80-pin devices (PIC18F8628/8723). This
module allows conversion of an analog input signal to a
corresponding 12-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 2-1, controls
the operation of the A/D module. The ADCON1
register, shown in Register 2-2, configures the
functions of the port pins. The ADCON2 register,
shown in Register 2-3, configures the A/D clock
source, programmed acquisition time and justification.
REGISTER 2-1: ADCON0: A/D CONTROL REGISTER 0
U-0
—
bit 7
U-0
R/W-0
R/W-0
R/W-0
—
CHS3
CHS2
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 7-6
bit 5-2
bit 1
bit 0
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)
1100 = Channel 12 (AN12)^(1,2)
1101 = Channel 13 (AN13)^(1,2)
1110 = Channel 14 (AN14)^(1,2)
1111 = Channel 15 (AN15)^(1,2)
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
Note 1: These channels are not implemented on PIC18F6628/6723 devices.
2: Performing a conversion on unimplemented channels will return a floating input measurement.
© 2007 Microchip Technology Inc.
Preliminary
DS39894A-page 29