Problem with 89S52

[rellutzu]

Honoured members,
As I am a newbie, I would shut my mouth, but this matter with 89s52
is very important to me , so please try to concentrate on it instead of whether P0 is collector or drain open!
Thank you !!!
And now here is the problem


Hello!
I "think" i have programmed a At89S52(at leat the flash is ok), but the logic levels at my ports are in the same state whether i use power on reset circuit or not! (it is not follwing the assembler code)!
I used standard 8051 POR circuit(8.2k + 10uf)!
Can you tell me if there are other values of these components for 89S52, or my chip has not been programmed?
Could it be burned?
Please reply me here or at rellutzu_1981@yahoo.com!
Thank you for your time!

EA should be 0v or 5V connected???


Yes, I can read the state of my flash, and the oscilator is the same one
i use in programming!
I added a reset button, but still the same problem : states at my ports are the same!


All of my ports are in the same state!
There is one more thing : just one of my external quartz has a voltage on its pin(in operantig mode). The other one doesn't!
Than how could I was able to program the flash?

 

[bmcculla]

It sounds like either the chip wasn't programmed or ther is something wrong with your program. Can you read back the state of the flash to se if it caontains your program? It's also possible that there is something wrong with your oscillator. It probably doesn't have anything to do with you POR circuit. You might want to add a resets button to maualy reset the circuit. Without more info thats all the help I can give.

Brent

 

[StupidDum]

Are them Port 0?? Port 0 is open collector.

 

[kinjalgp]

Are them Port 0?? Port 0 is open collector.

You mean "Open Drain". 8051 was intialally HMOS based and now all are manufactured using CMOS technology. No TTLs at all.

 

[StupidDum]

well..
i guess most ppl realise "open collector" in microcontroller actually means "open drain".
Using CMOS technology doesnt mean you cannot make an open drain port.

 

[Nigel Goodwin]

well..
i guess most ppl realise "open collector" in microcontroller actually means "open drain".
Using CMOS technology doesnt mean you cannot make an open drain port.

Yes, I always use 'open collector', I couldn't really care less about the technology inside the device - and open collector and open drain are basically the same thing.

 

[kinjalgp]

well..
i guess most ppl realise "open collector" in microcontroller actually means "open drain".
Using CMOS technology doesnt mean you cannot make an open drain port.

Yes, I always use 'open collector', I couldn't really care less about the technology inside the device - and open collector and open drain are basically the same thing.

There is no difference in the operation of both but use of proper jargons should be done whereever possible. Thats what I wanted to say.