Help in reprogramming ATTINY2313

[BOHDA]

reset attiny2313

One of my friends put me a question I couldn't respond-How to reprogram an ATTINY2313,after he made an mistake configuring pin Reset as I/O?Now the controller can't be seen at programming!
Any idea or advice?

 

[JURS]

attiny2313 isp

Hi BOHDA
I think that it is possible only in Parallel Programming.

JURS

 

[BOHDA]

attiny2313 parallel programming

What do you mean with parallel programming?He has an AVR Dongle programmer [74HC244] on LPT.He alredy tried at another guy to work on STK 500 board,but the same problem as above!

 

[silvio]

attiny2313 lpt

What do you mean with parallel programming?He has an AVR Dongle programmer [74HC244] on LPT.He alredy tried at another guy to work on STK 500 board,but the same problem as above!

I hope you know the purpose of RESET pin in ISP programming mode.
Well if you disable it and set as I/O you won't be able to program the circuit through ISP interface since you don't have control on RESET pin.
Thus you must program in what is called Parallel/High Voltage mode. As you can see in the picture +12v is applied to RESET pin. This "High Voltage" is provided by STK500 board.
Nevertheless an 8-bit data is applied parallel on PB7-PB6 and that is called parallel.
In ISP programming you performed what is called serial programming when only few pins are involved (your well known 74HC244 interface dongle).
Thus go to "another guy" and select inside STK500 programmer windows - Parallel/High Voltage Serial instead of ISP
See figure 2-3 on page 10 of STK500 user guide.
Read the page 19-23 as well for hardware settings.

Don't forget to set 1(unprogrammed) the FUSE RSTDISBL in order to gain again acces through ISP programming and not bother your friends every time when programming is required.

It's some confusing regarding the status of programmed and unprogrammed FUSE bits and the way is selected by the operator.
When an EEPROM cell is unprogrammed has an "1" logic.
When is programmed goes to "0" logic.
So take care what is the graphic mode used by your programmer for "0" and "1" interpretation and behaves accordingly.
If you don't know what's the purpose of FUSE bits leave them as default or read page 159-160 of Attiny2313 datasheet.

 

[BOHDA]

attiny2313 fuse bits

Thanks!I'll informed my friend about this![to try this trick]