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How can i set up DS89C420 serial programming circuit

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liquid

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programming ds89c420 via serial

How do I set up the serial programming circuit for the DS89C420. The diagram they give you in manual is very basic, it does not tell me enougth information. I got the HC125 and MAX232 chips and a 5V voltage regulator.
 

ds89c420 example

Hi liquid :)

I also recently got a DS89C420 and I managed to wire it up without resorting to the use of a 74HC125 as drawn in their circuit diagram.

Get a crystal, if you have a 10MHz that would do but your communications will be limited to 2400bps.

I drew up a little circuit for you.
 
Took some photographs of my setup

I know first hand how frustrating it is to try and get this working for the first time on a microprocessor so I will show you what the end result should look like on a bread board. I've RARed them up because they are quite high-res and I don't any good imaging software installed.

The regulator is in the top-right hand corner. You might be wondering what that white cable is on the left, that's just an end of a serial cable that I made which I've found very useful. You'll need to make one to connect your computer to your microcontroller. Ofcourse you can also stick wires from your serial port to the board but this solution isn't very elegant. :)

Good luck, I'd like to know how you went with getting access to the bootloader.
 
Thanks a lot!!!,,,,,u really saved me a lot of trouble :eek:

Iv got an exam the day after tomorrow, but as soon as thats over, ill be wiring it up and testing it out. Once iv done that, ill post how it went.

I've got myself a 16Mhz crystal, so ill be able to put that on 2* multiplyer to achieve 32Mhz :),,,,i also got a DB9 plug and header strip soo ill make myself a nice lookin serial cable too.

Im also doing mine on breadboard so its a great help havin those pictures you posted of your nice setup.

well, back to study...
 

Well, it worked fine, managed to connect to the loader successfully. I did however make use of the HC125N chip i got so i dont have to manually pull-up/down the right pins to enter the bootloader mode.
 

On the bitmap you have here it says the uC is AT89C52. Does it work with DS89c430?
 

Yes,,,,,,and it wont work with the AT micro,,,,,that just a little mistake
 

Do you have any PCB layout ? I'm afraid that I might make any mistake. For example Pin 4 of Conn D9 (DTR(, . Where it goes? Or pin 9 & 10 of max232. Where do they go?

Added after 6 minutes:

pins 7,8 of max232? The Gnd and Vcc of max 232? Vcc and Gnd of microprocessor?The RST of microprocessor?Goes to +5v?Does it need some reset circuit?(Resistor and Capacitor?)
 

dear,
Use mazidi as for reference book.
 

Hi

Where can find the C compiler and the software for programming the DS89C4x0.
I've one DS89C450 and like test.

thanks
 

abionnnn said:
Hi liquid :)

I also recently got a DS89C420 and I managed to wire it up without resorting to the use of a 74HC125 as drawn in their circuit diagram.

Get a crystal, if you have a 10MHz that would do but your communications will be limited to 2400bps.

I drew up a little circuit for you.
Click to expand...
will his work withh ds89c430?
 

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