PIC16F872-I/SP Microchip Technology Inc., PIC16F872-I/SP Datasheet - Page 81

• Manufacturer Part Number: PIC16F872-I/SP
• Description: 28 PIN, 7 KB FLASH, 128 RAM, 22 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC16F872-I/SP

• A/d Inputs: 5-Channel, 10-Bit
• Cpu Speed: 5 MIPS
• Eeprom Memory: 64 Bytes
• Input Output: 22
• Interface: I2C/SPI
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 28-pin SPDIP
• Programmable Memory: 3.5K Bytes
• Ram Size: 128 Bytes
• Speed: 20 MHz
• Timers: 2-8-bit, 1-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

10.0
The Analog-to-Digital (A/D) Converter module has five
input channels. The analog input charges a sample and
hold capacitor. The output of the sample and hold
capacitor is the input into the converter. The converter
then generates a digital result of this analog level via
successive approximation. The A/D conversion of the
analog input signal results in a corresponding 10-bit
digital number. The A/D module has high and low volt-
age reference input that is software selectable to some
combination of 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 clock must be derived from the
A/D’s internal RC oscillator.
REGISTER 10-1:
© 2006 Microchip Technology Inc.
ANALOG-TO-DIGITAL
CONVERTER (A/D) MODULE
bit 7-6
bit 5-3
bit 2
bit 1
bit 0
DD
, V
SS
ADCON0 REGISTER (ADDRESS: 1Fh)
bit 7
ADCS1:ADCS0: A/D Conversion Clock Select bits
00 = F
01 = F
10 = F
11 = F
CHS2:CHS0: Analog Channel Select bits
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
Unimplemented: Read as '0'
ADON: A/D On bit
1 = A/D converter module is operating
0 = A/D converter module is shut-off and consumes no operating current
Legend:
R = Readable bit
- n = Value at POR
, RA2 or RA3.
ADCS1
R/W-0
conversion is complete)
OSC
OSC
OSC
RC
(clock derived from the internal A/D module RC oscillator)
/2
/8
/32
ADCS0
R/W-0
R/W-0
CHS2
W = Writable bit
’1’ = Bit is set
R/W-0
CHS1
The A/D module has four registers. These registers
are:
• A/D Result High Register (ADRESH)
• A/D Result Low Register (ADRESL)
• A/D Control Register0 (ADCON0)
• A/D Control Register1 (ADCON1)
The ADCON0 register, shown in Register 10-1, con-
trols the operation of the A/D module. The ADCON1
register, shown in Register 10-2, configures the func-
tions of the port pins. The port pins can be configured
as analog inputs (RA3 can also be the voltage refer-
ence), or as digital I/O.
Additional information on using the A/D module can be
found in the PICmicro™ Mid-Range MCU Family Ref-
erence Manual (DS33023).
U = Unimplemented bit, read as ‘0’
’0’ = Bit is cleared
R/W-0
CHS0
GO/DONE
R/W-0
PIC16F872
x = Bit is unknown
U-0
—
DS30221C-page 79
R/W-0
ADON
bit 0