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NubegamerPT edited this page Sep 30, 2024 · 2 revisions

ASM Emulator Guide

Welcome to the ASM Emulator!
A simple and fun project designed to give you an introduction to assembly-like programming. Unlike real assembly language, this custom emulator gives you a controlled environment to explore without interacting directly with your CPU.

Disclaimer: This is a custom set of instructions (opcodes) created for learning purposes, and it doesn't interact with real hardware.

Table of Contents

How to Get Started

  1. Create a .s file: Write your assembly-like program using the opcodes listed below.
  2. Load the program: Run the program using the emulator, which will read and execute your .s file.

Available Commands (Opcodes)

Here is a list of available commands you can use in your ASM program. Each command corresponds to a specific operation.

1. load

  • Description: Loads an immediate value into a register.
  • Usage:
    load <register> <value>
    Example: load a8 13 — Loads the value 13 into the 8-bit register a8.

2. addi

  • Description: Adds an immediate value to a register.
  • Usage:
    addi <register> <value>
    Example: addi a8 5 — Adds 5 to the value in the 8-bit register a8.

3. subb

  • Description: Subtracts an immediate value from a register.
  • Usage:
    subb <register> <value>
    Example: subb b16 3 — Subtracts 3 from the value in the 16-bit register b16.

4. jmp

  • Description: Unconditional jump to a specific memory address. Execution continues from the specified address.
  • Usage:
    jmp [address]
    Example: jmp [0x0040] — Jumps to memory location 0x0040.

5. push

  • Description: Pushes the value of a register onto the stack.
  • Usage:
    push <register>
    Example: push a8 — Pushes the value in the 8-bit register a8 onto the stack.

6. pop

  • Description: Pops the top value from the stack into a register.
  • Usage:
    pop <register>
    Example: pop b16 — Pops the top value from the stack into the 16-bit register b16.

7. beq

  • Description: Branches to the specified address if two registers are equal.
  • Usage:
    beq <reg1> <reg2> [address]
    Example: beq a8 b8 [0x0100] — If a8 equals b8, jumps to address 0x0100.

8. bne

  • Description: Branches to the specified address if two registers are not equal.
  • Usage:
    bne <reg1> <reg2> [address]
    Example: bne a16 b16 [0x0100] — If a16 does not equal b16, jumps to address 0x0100.

9. beqz

  • Description: Branches to the specified address if the register value is zero.
  • Usage:
    beqz <register> [address]
    Example: beqz c8 [0x0080] — If c8 is 0, jumps to address 0x0080.

10. stl

  • Description: Stores the value from a register into a memory location.
  • Usage:
    stl <register> [address]
    Example: stl a8 [0x2000] — Stores the value from a8 into memory location 0x2000.

11. halt

  • Description: Halts program execution.
  • Usage:
    halt
    Example: halt — Stops the program execution.

12. null

  • Description: No operation (NOP). It does nothing and is used as a placeholder.
  • Usage:
    null
    Example: null — Skips this instruction.

Registers

The emulator supports the following registers. Each register is associated with a specific bit width or type:

  • a8: 8-bit register a

  • b8: 8-bit register b

  • c8: 8-bit register c

  • d8: 8-bit register d

  • a16: 16-bit register a

  • b16: 16-bit register b

  • c16: 16-bit register c

  • d16: 16-bit register d

  • af: Floating-point register a

  • bf: Floating-point register b

Example Program

Here’s an example of a simple ASM program:

load a8 10       ; Load value 10 into register a8
load b8 5        ; Load value 5 into register b8
addi a8 5        ; Add 5 to the value in register a8 (a8 becomes 15)
beq a8 b8 [end]  ; If a8 equals b8, jump to "end"
jmp [start]      ; Jump back to start (infinite loop)
end:
halt             ; Stop program execution
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