Custom 4-bit Processor Assembler

This repository contains an assembler for a custom 4-bit processor built using Logisim. The assembler is capable of converting assembly language instructions into machine code that can be executed by the processor.

Files

• Assembler.py: This is the main assembler script. It contains the Assembler class, which is responsible for parsing assembly language instructions and converting them into machine code.

• file_assemble.py: This script uses the Assembler class to convert an entire file of assembly language instructions into machine code.

Usage

To use the assembler, you need to have a file containing assembly language instructions. Each instruction should be on a separate line.

Here's an example of how to use the file_assemble.py script:

py file_assemble.py input.txt output.txt

In this example, input.txt is the file containing the assembly language instructions, and output.txt is the file where the machine code will be written.

Assembly Language Syntax

The assembler supports the following opcodes:

• NOP: No operation. This instruction does nothing.
• LD: Load. This instruction loads a value into a register.
• MOV: Move. This instruction moves a value from one register to another.
• DISP: Display. This instruction displays the combined value of two registers.
• XOR: Bitwise XOR. This instruction performs a bitwise XOR operation on the values of two registers.
• AND: Bitwise AND. This instruction performs a bitwise AND operation on the values of two registers.
• OR: Bitwise OR. This instruction performs a bitwise OR operation on the values of two registers.
• ADD: Add. This instruction adds the values of two registers.
• SUB: Subtract. This instruction subtracts the value of one register from another.

Each instruction should be written on a separate line. Operands should be separated by spaces. Register names should be written as R0, R1, etc.

Here's an example of an assembly language program:

LD R0 5
LD R1 10
LD R3 3
ADD R2 R0 R1
DISP {R2, R3}

This program loads the values 5 and 10 into registers R0 and R1, adds these values and stores the result in R2, and then displays the value of R2 and R3 to the ASCII display.