Assembly Language - Little mans computer

Página 1

Assembly Langauge

Machine code uses binary sequences to represent instructions and data on which they act.

Rather than having to remember which binary sequence represents which instruction, assembly code allows us to use mnemonics to represent these sequences.

As each assembly code instruction represents a machine code instruction, assembly code programs can often be much longer than their high-level equivalents.

Each processor has its own assembly language in this Case its little mans computer

Little mans computer uses 11 Instructions:

ADD - Add

SUB - Subtract

STA - Stores value from accumulator to memory

LDA - Loads Value from the memory to accumulator.

BRA - Branch Always

BRZ - Branch if zero

BRP - Branch if positive

INP - Input

OUT - Output

HLT - End Program

DAT - Data Location

Example:

INP

STA Num

ADD Num

OUT

HLT

Num DAT

What does it do?

Input a number and store it in accumulator

The contents of the accumulator are stored in the memory location labelled Num

The contents of Num are added to the accumulator

The contents of accumulator are outputted

The Program Ends

A location in memory is labelled Num