PIC16F874-10E/P Microchip Technology, PIC16F874-10E/P Datasheet - Page 86

• Manufacturer Part Number: PIC16F874-10E/P
• Description: IC MCU FLASH 4KX14 EE 40DIP
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F874-10E/P

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 10MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 33
• Program Memory Size: 7KB (4K x 14)
• Program Memory Type: FLASH
• Eeprom Size: 128 x 8
• Ram Size: 192 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 40-DIP (0.600", 15.24mm)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: PIC16F87410E/P

PICmicro MID-RANGE MCU FAMILY
5.2
5.3
5.4
DS31005A-page 5-4
General Instruction Format
Central Processing Unit (CPU)
Instruction Clock
The Mid-Range MCU instructions can be broken down into four general formats as shown in
Figure
opcode size is what allows 35 instructions to be implemented.
Figure 5-1: General Format for Instructions
The CPU can be thought of as the “brains” of the device. It is responsible for fetching the correct
instruction for execution, decoding that instruction, and then executing that instruction.
The CPU sometimes works in conjunction with the ALU to complete the execution of the instruc-
tion (in arithmetic and logical operations).
The CPU controls the program memory address bus, the data memory address bus, and
accesses to the stack.
Each instruction cycle (T
as the device oscillator cycle time (T
Decode, Read, Process Data, Write, etc., of each instruction cycle. The following diagram shows
the relationship of the Q cycles to the instruction cycle.
The four Q cycles that make up an instruction cycle (T
Each instruction will show a detailed Q cycle operation for the instruction.
Figure 5-2: Q Cycle Activity
Bit-oriented file register operations
Byte-oriented file register operations
Literal and control operations
General
CALL and GOTO instructions only
Q1:
Q2:
Q3:
Q4:
13
13
13
13
5-1. As can be seen the opcode for the instruction varies from 3-bits to 6-bits. This variable
Tosc
OPCODE
OPCODE
OPCODE
OPCODE
Instruction Decode Cycle or forced No operation
Instruction Read Data Cycle or No operation
Process the Data
Instruction Write Data Cycle or No operation
11
Q1
10 9
10
8
Q2
CY
b (BIT #)
d
T
7
) is comprised of four Q cycles (Q1-Q4). The Q cycle time is the same
8
CY
Q3
1
6
7
7 6
k (literal)
Q4
f (FILE #)
k (literal)
OSC
f (FILE #)
Q1
). The Q cycles provide the timing/designation for the
Q2
0
0
0
0
T
CY
Q3
2
CY
) can be generalized as:
Q4
d = 0 for destination W
d = 1 for destination f
f = 7-bit file register address
b = 3-bit bit address
f = 7-bit file register address
k = 8-bit immediate value
k = 11-bit immediate value
Q1
1997 Microchip Technology Inc.
Q2
T
CY
Q3
3
Q4