PCP

Theme:

General Purpose Processor - Pocket Calculator

Project Technical Specifications:

Components:

• 2 general purpose registers: X, Y
• 1 accumulator A
• ALU
• Control Unit
• Instruction and Data memory (Including Stack)
• Sign Extend Unit
• Processor registers: PC, SP, Flag

Sizes:

• Registers:

  • 16-bit Accumulator
  • 2 of 16-bit general purpose (GP) registers: X and Y
  • 4-bit Flag register: Zero, Negative, Carry, Overflow
  • 16-bit stack pointer
  • 6-bit Program Counter

• Instructions:

  • 16-bit instruction size
    • 6-bit op-code
    • 1-bit Register address
    • 9-bit Immediate size ( [-256:255] )

• Word:

  • 16-bit word size

• Stack:

  Grows inverse in memory

Instructions:

Memory instructions:

• Load
• Store

Opcode	Register Address	Immediate
6 bit	1 bit	9 bit

Branch instructions:

• BRZ = brach if zero
• BRN = branch if negative
• BRC = branch if carry
• BRO = branch if overflow
• BRA = branch always (unconditional branch)
• JMP = call procedure
• RET = return from procedure

Opcode	Address
6 bit	10 bit

ALU:

• ADD
• SUB
• LSR
• LSL
• RSR
• RSL
• MOV
• MUL
• DIV
• MOD
• AND
• OR
• XOR
• NOT
• CMP
• TST
• INC
• DEC

Opcode	Register Address	Immediate
6 bit	1 bit	9 bit

Additional operations:

• Logarithm
• Factorial
• Module
• Sin