PIC18C658 MICROCHIP [Microchip Technology], PIC18C658 Datasheet - Page 230

• Manufacturer Part Number: PIC18C658
• Description: High-Performance Microcontrollers with CAN Module
• Manufacturer: MICROCHIP [Microchip Technology]

PIC18CXX8
The analog reference voltage is software selectable to
either the device’s positive and negative supply voltage
(V
RA3/AN3/V
The A/D converter has a unique feature of being able to
operate while the device is in SLEEP mode. To operate
in SLEEP, the A/D conversion clock must be derived
from the A/D’s internal RC oscillator.
The output of the sample and hold is the input into the
converter, which generates the result via successive
approximation.
A device RESET forces all registers to their RESET
state. This forces the A/D module to be turned off and
any conversion is aborted.
FIGURE 18-1: A/D BLOCK DIAGRAM
DS30475A-page 230
DD
and V
Note 1: Channels AN15 through AN12 are not available on the PIC18C658.
REF
2: I/O pins have diode protection to V
SS
+ pin and RA2/AN2/V
Converter
), or the voltage level on the
10-bit
A/D
Reference
Voltage
REF
V
V
-.
REF
REF
Advanced Information
+
-
(Input Voltage)
VCFG1:VCFG0
V
AIN
DD
and V
V
SS
DD
.
Each port pin associated with the A/D converter can
be configured as an analog input (RA3 can also be a
voltage reference), or as a digital I/O.
The ADRESH and ADRESL registers contain the result
of the A/D conversion. When the A/D conversion is
complete,
ADRESH/ADRESL
(ADCON0 register) is cleared, and A/D interrupt flag bit
ADIF is set. The block diagram of the A/D module is
shown in Figure 18-1.
V
SS
CHS3:CHS0
the
result
1111
1110
1101
1100
1011
1010
1001
1000
0111
0110
0101
0100
0011
0010
0001
0000
registers,
2000 Microchip Technology Inc.
is
the
loaded
GO/DONE
AN15
AN14
AN13
AN12
AN11
AN10
AN9
AN8
AN7
AN6
AN5
AN4
AN3
AN2
AN1
AN0
into
(1)
(1)
(1)
(1)
the
bit