89V51RD2 LED Interfacing Source Code

89V51RD2 is 8 bit microcontroller from 8051 family. This is made by NXP (Philips) and considered as entry level microcontroller for learning and product designing. ATMEL’s 89C51 or 89S52 are also pin as well as code compatible microcontrollers for 89V51RD2. In other words 89S51, 89C51, 89S52, 89C52 and 89V51RD2 can be replace each other, with certain restrictions. These microcontrollers have different memory size and have some unique features of their own. Thus blind replacement of these controllers is not possible.

Let’s understand as “How to interface a simple LED with P89V51RD2?”

These experiments are performed using 89V51RD2 Starter Kit.

Beginners and experts use this all in one board to learn the microcontrollers and test product prototypes.

Connections for this experiment:

1.                  Connect 8 wire connectors between P1 of 89V51RD2 and LEDs

2.                  Connect P3.0, P3.1 and RST to ISP programming (RS232 section)

3.                  Connect 9VDC supply to the board

Experiment 1: All LEDs ON

;Connect 8 LEDs to P1

Start:

        MOV P1,#00h

Loop:

        sjmp Loop

Experiment 2: All LEDs OFF

;Connect 8 LEDs to P1

Start:

        MOV P1,#0FFh

Loop:

        sjmp Loop

Experiment 3: Alternate LEDs ON

;Connect 8 LEDs to P1

Start:

        MOV P1,#55h

Loop:

        sjmp Loop

Experiment 4: Only One LED ON

;Connect 8 LEDs to P1

Start:

        MOV P1,#0ffh

        CLR P1.0

Loop:

        sjmp Loop

In above experiments, various values are assigned to Port 1.

Loop is a label used to create never ending loop, remember that programs / applications for microcontroller never ends or terminates.

Try these sample codes for LED interfacing with 89V51RD2 and observe their results.