PIC16F871-I/PT Microchip Technology Inc., PIC16F871-I/PT Datasheet - Page 81

• Manufacturer Part Number: PIC16F871-I/PT
• Description: 44 PIN, 7 KB FLASH, 128 RAM, 33 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC16F871-I/PT

• A/d Inputs: 8-Channel, 10-Bit
• Cpu Speed: 5 MIPS
• Eeprom Memory: 64 Bytes
• Input Output: 33
• Interface: USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 44-pin TQFP
• 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
inputs for the 28-pin devices and eight for the other
devices.
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 dig-
ital result of this analog level via successive approxima-
tion. 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 voltage reference input
that is software selectable to some combination of V
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:
 2003 Microchip Technology Inc.
SS
, RA2, or RA3.
ANALOG-TO-DIGITAL (A/D)
CONVERTER MODULE
bit 7-6
bit 5-3
bit 2
bit 1
bit 0
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)
010 = Channel 2, (RA2/AN2)
011 = Channel 3, (RA3/AN3)
100 = Channel 4, (RA5/AN4)
101 = Channel 5, (RE0/AN5)
110 = Channel 6, (RE1/AN6)
111 = Channel 7, (RE2/AN7)
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
ADCS1
R/W-0
Note 1: These channels are not available on the PIC16F870 device.
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
DD
W = Writable bit
‘1’ = Bit is set
(1)
(1)
(1)
,
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
reference), or as digital I/O.
Additional information on using the A/D module can be
found in the PICmicro™ Mid-Range MCU Family
Reference Manual (DS33023).
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
R/W-0
CHS0
PIC16F870/871
GO/DONE
R/W-0
x = Bit is unknown
U-0
—
DS30569B-page 79
R/W-0
ADON
bit 0