PIC18F6X2X Datasheet, PDF (237/386 Pages) Microchip Technology – 64/80-Pin High Performance, 64-Kbyte Enhanced FLASH Microcontrollers with A/D

PIC18F6X2X/8X2X
20.0 10-BIT ANALOG-TO-DIGITAL
CONVERTER (A/D) MODULE
The analog-to-digital (A/D) converter module has 12
inputs for the PIC18F6X2X devices and 16 for the
PIC18F8X2X devices. This module allows conversion
of an analog input signal to a corresponding 10-bit
digital number.
A new feature for the A/D converter is the addition of pro-
grammable acquisition time. This feature allows the user
to select a new channel for conversion and setting the
GO/DONE bit immediately. When the GO/DONE bit is
set, the selected channel is sampled for the pro-
grammed acquisition time before a conversion is actu-
ally started. This removes the firmware overhead that
may have been required to allow for an acquisition
(sampling) period (see Register 20-3 and Section 20.4).
REGISTER 20-1:
ADCON0 REGISTER
U-0
U-0
R/W-0
—
—
CHS3
bit 7
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 20-1, con-
trols the operation of the A/D module. The ADCON1
register, shown in Register 20-2, configures the func-
tions of the port pins. The ADCON2, shown in
Register 20-3, configures the A/D clock source,
justification and auto-acquisition time.
R/W-0
CHS2
R/W-0
CHS1
R/W-0
CHS0
R/W-0
GO/DONE
R/W-0
ADON
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)
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 PIC18F6X2X (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
- 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
DS39612A-page 235