A simple instruction set Assembler

BIT CRUNCHER

BIT CRUNCHER is a simple instruction set assembler. An assembler converts assembly language code written in mnemonic language into machine language code or binary code for the intended host machine. Bit Cruncher is a hypothetical assembler, developed for educational purposes rather than using it as a real assembler. The BIT CRUNCHER operates on the instruction set provided on the righthand side of the page and the binary code is intended to be hosted on this hypothetical architecture only.

Using it:

Follow the instructions provided below for generating the machine code for your own assembly code.

1) Select your file by clicking on the 'BROWSE' button and choosing it from the file-tree.

2) If you want to view or recheck the file click on 'OPEN'.

3) Once you have selected the file, the path will appear in the text field above.

4) Simply click on the 'ASSEMBLE' button to assemble the input file.

5) If your input file is named ABC.asm the output file machine_code_ABC.bin will be created in the folder of BIT CRUNCHER.

Simple Instruction Set

Memory consists of bytes with 2 consecutive bytes forming a word. All addresses are byte addresses. There are a total of 256 bytes in computer memory, starting from 0 to 255.

There are four registers: A (accumulator), B, C and D. Each register is 8 bits in length.

Integers are stored as 8 bit binary numbers.

All machine instructions have the following 16 bit format. The detailed structure of the instruction format is shown below.

The basic set of instructions include:

1. ADD

2. SUB

3. LOAD

4. STORE

5. CMP (Compare)

6. JLT (Jump if less than)

7. JEQ (Jump if equal)

8. JGT (Jump if greater than)

Mnemonic	Indication	Operand 1 (optional)	Operand 2 (optional)
Opcode (4 bit)	X (2 bit)	Register (2 bit)	Address / value (8 bit)

X = 0 indicates register, 1 indicates memory address, 2 indicates value, 3 indicates no operand

Code for registers: A: 1, B: 2, C: 3, D: 4

Project Report with source code:
https://docs.google.com/leaf?id=0B-mmfn2DeWvJMDI3MDlhZTctNTYwMy00MTkxLWIzZjYtYjJlNzBjNzM4M2Vl&hl=en