PIC16F877T-20/L Microchip Technology, PIC16F877T-20/L Datasheet - Page 73

• Manufacturer Part Number: PIC16F877T-20/L
• Description: IC MCU FLASH 8KX14 EE 44PLCC
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F877T-20/L

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 33
• Program Memory Size: 14KB (8K x 14)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 368 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: External
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 44-PLCC
• For Use With: DVA16XL441 - ADAPTER DEVICE ICE 44PLCC309-1040 - ADAPTER 44-PLCC ZIF TO 40-DIP309-1039 - ADAPTER 44-PLCC TO 40-DIP
• 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