89V51XX PROGRAMMER USING SERIAL PORT

89v51xx series are very special series of microcontrollers in 8051 family as

they are dead easy to burn and these microcontrollers have more flash memory

compared to 89s series and 89c series.

these microcontrollers are manufactured by NXP(founded by philips).

they are boon to the beginners who dont have a parallel port and cannot make

89sxx serial programmer,as microcontrollers are "IN SYSTEM PROGRAMMABLE"(ISP)

these micro controllers have ISP through UART.which means that,it requires only one level conversion MAX232 ic between the computer serial port and the microcontroller.more

about level conversion in my previous tutorial,IC MAX232 FOR INTERFACING COMPUTER USING RS-232 WITH EXTERNAL HARDWARE(µc or µp)

the burning process is carried out only by two pins TXD(transmit) and

RXD(receive).and the program is burned to FLASH ROM via UART through these

pins.

89v51RD2 programmer circuit:

click on image to enlarge

Download schematic pdf here

Download Flash magic software(flash magic website)

89v51rx2.h headerfile download for keil IDE programming in 'c'

software tools:

After the circuit is connected as shown in the above schematic,we should use

a software to send the program bits(burn) in to the microcontrollers FLASH ROM

the software specially dedicated for this philips microcontrollers is

called "FLASH MAGIC".

detailed step by step procedure is given with snapshots below.

step1:

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select the device name,am using 89v51RD2 here as an example.

step2:

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select com port as com1 and make sure that no other peripherals are connected

to com port.

step3:

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select moderate baud rate,choose minimum while you work for the first time

later you can increase to optimum,by increasing step by step.

step4:

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select interface as none(isp).

step5:

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browse for the .hex file to be burned to the microcontroller.

step6:

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now click start buttton,this starts burning process.

step7:

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the burning status is shown in the bar.

step8:

------

when the burning process is finished,you get the "finish" message.

now your device is programmed successfully!!!!

so enjoy!!!!:)

EXTRA READING:

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1.some microcontrollers which support this method are 89v51RD2,89v51RB2,

89v51Rc2,89v52x2,89v660,89v662,89v664....etc.

2.you can remove the connection between the RESET and DTR and manually make

RESET high immediatly when the software is ready to start programming.

3.in the circuit given above,the RESET is connected to the DTR pin of serial

port,this takes care of making the RESET high during the burning process.

meaning whenever serial port is ready to burn ,it asserts DTR

(data terminal ready)pin(pin4 of DB-9)and hence making the RESET to go high.

4.one more speciality is that these microcontrollers can also be burnt

through parallelport method given in my previous tutorial.

5.if any program changes are made,the .hex file is automatically updated,no need

to select it again.

****any queries or comments ??? just post them here,or mail me,Thank you!!!!!!!!**********

-Regards

venkatesh