Question

In the PIC18F452 Programming Model, list 2 registers that are used to access the Program Memory. Indicate their sizes.

Answer 1

PIC18 has 18 to 100 pins and up to 128kb of flash memory.

The representation of the internal architecture of a processor, necessary to write assembly language programs.

• Programming model

Two groups of registers in PIC16 8bit programming model

• ALU Arithmetic Logic Unit (ALU)
• Special Function Registers (SFR's) from data memory.

ALU WREG Status Instruction decoder

Registers Bank Select Registers File select registers Program counter

Control Unit

Data memory up to 4k bytes divided into 256 byte Banks.

Access bank 256 bytes

Access RAM 00h to 7Fh

Access SFR 80h to FFh

Register File concept: All of data memory is part of the register file, so any location in data memory may be operated directly.

All peripherals are mapped into data memory as a series of registers.

All instructions can operate on any data memory location.

Special Function registers F80h to FFFh Input output Ports Interrupts EE PROM Serial I/O ports Timer CCP(having multiple memory) A/D converter Synchronous Serial I/O Miscellaneous Functions

WREG

• 8- bit Working Register i.e. equivalent to an accumulator
• Used for arithmetic and logic operations

BSR: Bank Select Registers 0 to F

• 4 bit register.
• Only low ordee four bits are used to provide MSB four bits of a 12 bit address of data memory.

Thank you.