PIC16F877A-I/PT Microchip Technology Inc., PIC16F877A-I/PT Datasheet - Page 123

• Manufacturer Part Number: PIC16F877A-I/PT
• Description: 44 PIN, 7 KB FLASH, 368 RAM, 33 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC16F877A-I/PT

• A/d Inputs: 8-Channel, 10-Bit
• Comparators: 2
• Cpu Speed: 5 MIPS
• Eeprom Memory: 256 Bytes
• Input Output: 33
• Interface: I2C/SPI/USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 44-pin TQFP
• Programmable Memory: 14K Bytes
• Ram Size: 368 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

12.2
12.2.1
The PIC16F87X can be operated in four different oscil-
lator modes. The user can program two configuration
bits (FOSC1 and FOSC0) to select one of these four
modes:
• LP
• XT
• HS
• RC
12.2.2
In XT, LP or HS modes, a crystal or ceramic resonator
is connected to the OSC1/CLKIN and OSC2/CLKOUT
pins to establish
PIC16F87X oscillator design requires the use of a par-
allel cut crystal. Use of a series cut crystal may give a
frequency out of the crystal manufacturers specifica-
tions. When in XT, LP or HS modes, the device can
have an external clock source to drive the OSC1/
CLKIN pin (Figure 12-2).
FIGURE 12-1:
2001 Microchip Technology Inc.
Note 1: See Table 12-1 and Table 12-2 for recom-
C1
C2
2: A series resistor (R
3: RF varies with the crystal chosen.
Oscillator Configurations
(1)
(1)
mended values of C1 and C2.
strip cut crystals.
Low Power Crystal
Crystal/Resonator
High Speed Crystal/Resonator
Resistor/Capacitor
CRYSTAL OSCILLATOR/CERAMIC
RESONATORS
OSCILLATOR TYPES
XTAL
R
s
(2)
OSC1
OSC2
oscillation (Figure 12-1).
CRYSTAL/CERAMIC
RESONATOR OPERATION
(HS, XT OR LP
OSC CONFIGURATION)
s
) may be required for AT
RF
(3)
PIC16F87X
SLEEP
To
Internal
Logic
The
FIGURE 12-2:
TABLE 12-1:
All resonators used did not have built-in capacitors.
16.0 MHz
These values are for design guidance only.
See notes following Table 12-2.
455 kHz
2.0 MHz
4.0 MHz
8.0 MHz
Clock from
Ext. System
Mode
HS
XT
Panasonic EFO-A455K04B
Murata Erie CSA16.00MX
16.0 MHz
Murata Erie CSA2.00MG
Murata Erie CSA4.00MG
Murata Erie CSA8.00MT
Open
455 kHz
2.0 MHz
4.0 MHz
8.0 MHz
Freq.
Resonators Used:
CERAMIC RESONATORS
Ranges Tested:
EXTERNAL CLOCK INPUT
OPERATION (HS, XT OR
LP OSC
CONFIGURATION)
PIC16F87X
68 - 100 pF
OSC1
OSC2
15 - 68 pF
15 - 68 pF
10 - 68 pF
10 - 22 pF
OSC1
PIC16F87X
DS30292C-page 121
68 - 100 pF
15 - 68 pF
15 - 68 pF
10 - 68 pF
10 - 22 pF
OSC2
0.3%
0.5%
0.5%
0.5%
0.5%