PIC16F872-E/SS Microchip Technology, PIC16F872-E/SS Datasheet - Page 73

• Manufacturer Part Number: PIC16F872-E/SS
• Description: IC,MICROCONTROLLER,8-BIT,PIC CPU,CMOS,SSOP,28PIN,PLASTIC
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F872-E/SS

• Rohs Compliant: YES
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 22
• Program Memory Size: 3.5KB (2K x 14)
• Program Memory Type: FLASH
• Eeprom Size: 64 x 8
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Data Converters: A/D 5x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 28-SSOP
• Package: 28SSOP
• Device Core: PIC
• Family Name: PIC16
• Maximum Speed: 20 MHz
• Operating Supply Voltage: 5 V
• Data Bus Width: 8 Bit
• Number Of Programmable I/os: 22
• Interface Type: I2C/SPI
• On-chip Adc: 5-chx10-bit
• Number Of Timers: 3
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

4.2
1997 Microchip Technology Inc.
OSC2/CLKOUT
(RC mode)
Clocking Scheme/Instruction Cycle
OSC1
Q4
PC
Q2
Q3
Q1
The clock input (from OSC1) is internally divided by four to generate four non-overlapping
quadrature clocks, namely Q1, Q2, Q3, and Q4. Internally, the program counter (PC) is incre-
mented every Q1, and the instruction is fetched from the program memory and latched into the
instruction register in Q4. The instruction is decoded and executed during the following Q1
through Q4. The clocks and instruction execution flow are illustrated in
Example
Figure 4-3: Clock/Instruction Cycle
Q1
Execute INST (PC-1)
Fetch INST (PC)
Q2
T
4-1.
CY
PC
1
Q3
Q4
Q1
Execute INST (PC)
Fetch INST (PC+1)
Section 4. Architecture
Q2
T
PC+1
CY
2
Q3
Q4
Q1
Execute INST (PC+1)
Fetch INST (PC+2)
Q2
T
PC+2
CY
3
Q3
Q4
DS31004A-page 4-5
Figure
Internal
phase
clock
4-3, and
4