PIC16C63A Microchip Technology, PIC16C63A Datasheet - Page 75

• Manufacturer Part Number: PIC16C63A
• Description: 28/40-Pin 8-Bit CMOS Microcontrollers
• Manufacturer: Microchip Technology

10.0
This section applies to the PIC16C73B and
PIC16C74B only. The analog-to-digital (A/D) converter
module has five inputs for the PIC16C73B, and eight for
the PIC16C74B.
The A/D allows conversion of an analog input signal to
a corresponding 8-bit digital number (refer to Applica-
tion Note AN546 for use of A/D Converter). The output
of the sample and hold is the input into the converter,
which generates the result via successive approxima-
tion. The analog reference voltage is software select-
able to either the device’s positive supply voltage (V
or the voltage level on the RA3/AN3/V
The A/D converter has a unique feature of being able
to operate while the device is in SLEEP mode. To oper-
ate in sleep, the A/D conversion clock must be derived
from the A/D’s internal RC oscillator.
FIGURE 10-1: ADCON0 REGISTER (ADDRESS 1Fh)
1998 Microchip Technology Inc.
bit7
bit 7-6: ADCS1:ADCS0: A/D Conversion Clock Select bits
bit 5-3: CHS2:CHS0: Analog Channel Select bits
bit 2:
bit 1:
bit 0:
ADCS1 ADCS0
R/W-0
ANALOG-TO-DIGITAL
CONVERTER (A/D) MODULE
00 = F
01 = F
10 = F
11 = F
000 = channel 0, (RA0/AN0)
001 = channel 1, (RA1/AN1)
010 = channel 2, (RA2/AN2)
011 = channel 3, (RA3/AN3)
100 = channel 4, (RA5/AN4)
GO/DONE: A/D Conversion Status bit
If ADON = 1
1 = A/D conversion in progress (setting this bit starts the A/D conversion)
0 = A/D conversion not in progress (This bit is automatically cleared by hardware when the A/D conversion
is complete)
Unimplemented: Read as '0'
ADON: A/D On bit
1 = A/D converter module is operating
0 = A/D converter module is shutoff and consumes no operating current
R/W-0
OSC
OSC
OSC
RC
(clock derived from an internal RC oscillator)
/2
/8
/32
R/W-0
CHS2
R/W-0
CHS1
REF
pin.
R/W-0
CHS0
DD
GO/DONE
PIC16C63A/65B/73B/74B
)
R/W-0
Additional information on the A/D module is available in
the
(DS33023).
The A/D module has three registers. These registers
are:
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.
The ADCON0 register, shown in Figure 10-1, controls
the operation of the A/D module. The ADCON1 regis-
ter, shown in Figure 10-2, configures the functions of
the port pins. The port pins can be configured as ana-
log inputs (RA3 can also be a voltage reference) or as
digital I/O.
• A/D Result Register (ADRES)
• A/D Control Register 0 (ADCON0)
• A/D Control Register 1 (ADCON1)
U-0
—
PICmicro
ADON
R/W-0
bit0
Mid-Range
R = Readable bit
W = Writable bit
U = Unimplemented bit,
- n = Value at POR reset
read as ‘0’
Reference
DS30605A-page 75
Manual,