Introduction of Microntroller

Microcontroller design is highly user friendly. Only requirement is to raise questions in our mind! Of course, because it is logical subject.

To understand the all actions, we should follow instructions based approach. Instructions will generate required signals and configurations of hardware with its main function. For example, MOVX instruction transfers data with external RAM and also sends logic high or low on RD/WR pins. In this sense it’s a user friendly to deign engineer, because instructions will do required interfacing activations.


So, during study of 8051 keep track with instructions. Don’t try to understand hardware working and configuration alone but realize every working step with help of instructions.

What should learn first, Hardware or software? Without knowledge of hardware its not possible to write fully 8051 utilized program. But to understand hardware functions, we need to learn instruction set and also to write programs which helpful to understand hardware functions. Keeping in mind to make easy learning by this approach, We should learn instruction set first.

8051 uC has following salient features:

Four Bidirectional I/O Parralel Ports
One Full Duplex serial Port
Two 16-Bit Programmable Timer/Counters
Bit and Byte Addressing
128 Bytes RAM including 128 bit addressable Space
4kB Flash Memory
DC to 33MHz Operation
Power down and Idle mode for power saving
Five Programmable Interrupt Sources

AT89C51 microcontrooler datasheet from ATMEL and DS89c450 microcontroller datasheet from Dallas Semiconductor was taken as a prime reference throughout the discussion of the blog.