PIC16F72-I/SP Microchip Technology Inc., PIC16F72-I/SP Datasheet - Page 20

• Manufacturer Part Number: PIC16F72-I/SP
• Description: 28 PIN, 3.5 KB FLASH, 128 RAM, 22 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC16F72-I/SP

• A/d Inputs: 5-Channel, 8-Bit
• Cpu Speed: 5 MIPS
• Eeprom Memory: 0 Bytes
• Input Output: 22
• Interface: I2C/SPI
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 28-pin SPDIP
• 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

PIC16F72
2.3
The program counter (PC) specifies the address of the
instruction to fetch for execution. The PC is 13-bits
wide. The low byte is called the PCL register. This reg-
ister is readable and writable. The high byte is called
the PCH register. This register contains the PC<12:8>
bits and is not directly readable or writable. All updates
to the PCH register go through the PCLATH register.
FIGURE 2-3:
DS39597B-page 18
PCL and PCLATH
Example 1 - Instruction with PCL as destination
Example 2 - GOTO Instruction
Example 3 - CALL Instruction
Example 4 - RETURN, RETFIE, or RETLW Instruction
Note: PCLATH is not updated with the contents of PCH.
LOADING OF PC IN DIFFERENT SITUATIONS
PC
PC
PC
PC
12
12
2
12
12
2
11 10
11 10
11 10
5
PCH
PCLATH<4:3>
PCH
PCH
PCLATH<4:3>
PCH
PCLATH
PCLATH
PCLATH
PCLATH<4:0>
8
8 7
8 7
PCLATH
8
7
7
PCL
PCL
PCL
PCL
11
11
11
8
ALU result
0
0
0
0
13
13
Opcode <10:0>
Opcode <10:0>
Opcode <10:0>
Figure 2-3 shows the four situations for the loading of
the PC.
• Example 1 shows how the PC is loaded on a write
• Example 2 shows how the PC is loaded during a
• Example 3 shows how the PC is loaded during a
• Example 4 shows how the PC is loaded during
to PCL (PCLATH<4:0> → PCH).
GOTO instruction (PCLATH<4:3> → PCH).
CALL instruction (PCLATH<4:3> → PCH), with
the PC loaded (PUSH’d) onto the Top-of-Stack.
one of the return instructions, where the PC is
loaded (POP’d) from the Top-of-Stack.
Stack (13-bits x 8)
Stack (13-bits x 8)
Stack (13-bits x 8)
Stack (13-bits x 8)
Top-of-Stack
Top-of-Stack
Top-of-Stack
Top-of-Stack
 2002 Microchip Technology Inc.