AT89S52

[stigma]

Hello!

My Atmel AT89S52 controller (MCS-51 8052 based) controller arived today.
I got a few questions about this chip, does it require an external XTAL to run even though it got an builtin oscilator ? I tried to get some led's to blink, but it would'nt work.. Could it be because i need an external XTAL circuit connected to the two XTAL inputs ? I would also really appericate if someone could come up with some good links with tutorials and software for this chip (i use a programmer called PX-1000). I also got an PIC16F628 chip, but it seems it wouldn't work with my Picstart Plus programmer (says it needs newer firmware) how do i upgrade this firmware ? Can i just somehow flash it or do i need to change some components inside the programmer ?

Regards, stigma

 

[kinjalgp]

You need to connect a crystal across pin 18 and 19 of AT89S52 along with two 33pF capacitors connected between both these pins and ground.

I think Microchip provides firmware update for PICStart Plus in the form of compiled hex file. Search www.microchip.com for it.

 

[Nigel Goodwin]

I also got an PIC16F628 chip, but it seems it wouldn't work with my Picstart Plus programmer (says it needs newer firmware) how do i upgrade this firmware ? Can i just somehow flash it or do i need to change some components inside the programmer ?

As kinjalgp says, you can download later firmware from MicroChip as a HEX file - from what I vaguely remember (never having seen a PICStart+) you need an OTP chip to blow it into. I also have a vague recollection that the later PICStart+'s use a reprogrammable FLASH chip, you should be able to find all the details of what you can and can't do at MicroChip.

 

[stigma]

Thanks

Thanks for answers!

Why do i need the two condensators ? And is the 33pf value important ?

 

[Nigel Goodwin]

Re: Thanks

Why do i need the two condensators ? And is the 33pf value important ?

Well, they stopped being called 'condensors' 30-40 years ago, but us 'older ones' still know what you mean 8)

Yes, you do need them, they are part of the oscillator circuit, but the value isn't at all critical - I use anything between 10pF and 50pF, as long as they are both the same (you can alter one slightly to trim the frequency).