Am finally back after a long break. I didn't mean to stay this long; am really sorry about that.

Now straight to business. We have defined the terms, Embedded system and Microcontroller, and have also mentioned a few tools (hardware & software) that we'll be needing to kick start our embedded designs. I also mentioned that 8051 microcontroller family would be our reference in the course of this tutorial.


Before I proceed, I still want to reassure you that if you take this tutorial seriously, it is doubtful that you will not
grab a working understanding of embedded systems design. Having said that, lets move on straight to our lessons.

One more thing, its important that we trash the difference between a general purpose microprocessor and microcontroller now to avoid possible future confusions.

General Purpose Microprocessor:

1. has no ROM
2. has no RAM
3. has no input/Output (I/O) ports
4. has no timers




Microcontroller:

1. Contains Microprocessor
2. has ROM
3. has RAM
4. has I/O ports
5. has timers
6. might have ADC and other peripherals


P.S if you are working with microprocessors, you must interface with external ROM, RAM & I/O ports, Timers for them to

function (this makes the system bulkier and more expensive than microcontroller based systems - though it has the versatility on the amount of memory and ports)

P.P.S The fixed amount of on-chip ROM, RAM,and number of I/O ports makes microcontrollers ideal for many applications in which cost and space are critical.


[size=16pt]Now straight to 8051 Micro[/size]

---

8051 Microcontroller

8051 is quite an old guy in the world of micros, yet it has maintained its popularity over the years, thus, making it our right choice. After learning how to program this guy, you will have the choice of working with a wide range of micros that have been developed using its architecture. (eg AT89C51 by ATMEL)


lets quickly take a look at some of the features of the basic 8051 microcontroller.


1. 8051 has an 8 bit processor(this can only work on 8bits data at a time)

2. 8051 is a 40 pin (dip) chip

3. 8051 has 32 input/output pins

4. 8051 has 4 ports each is 8bit wide (Port0(P0.0 - p0.7), Port1(P1.0 to P1.7), Port2(P2.0 to p2.7), and Port3(P3.0 to

p3.7))

4. 8051 has 4k byte of onchip memory (code memory(EPROM) new variants have EEPROM and/or FLASH memory)

6. 8051 has 128 byte of usable internal RAM (data memory) and another 128byte of unusable RAM

7. 8051 has 8 general purpose registers (R0 to R7)

8. 8051 has 20 special function registers (Accummulator (A), Stack Pointer (SP), TMOD etc)

9. 8051 has the capacitity to address a maximum of 64Kbyte of external memory (having 16 Address lines A0 - A15)

10. 8051 has 2 timers

11. 8051 has 1 USART (serial port)

12. 8051 has 6 interrupt sources

I dey follow you jare.

This is interesting...continue

This class just dey dormant,what happened