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Jan Waclawek
01/08/12 15:05
  01/08/12 15:05

Read: 1071 times

#185378 - AT89S8253 ISP
Responding to: ???'s previous message
The '51 development crew of Atmel has a nasty habit of re-inventing the ISP protocol with every generation of the chips.

So the first SPI-ISPable AT89S8252 (and IIRC the short-lived 'S53, but I may be wrong here) had a 3-byte protocol, which was changed to 4-bytes (similar to the AVR's except for the RESET polarity) in the 'S51/'S52. The new 'LPs introduced one or two (depending on particular 'LP model) extra bytes before the commands (making them 5- and 6-bytes effectively), and an extra signal too, which makes it even more pain in the **** due to hardware incompatibility with the previous chips and the AVRs (the various polarity reset is only a minor nuisance then compared to those...).

The 'S8253 (and the 'S2051/'S4051) has 4-byte protocol, but for extra fun, the clock polarity is different (and also the order of first clock-first data is different, see the 4 SPI modes). That's why it's not enough to reconfigure avrdude (probably - I'd need to check) but you need to fix that in code, too.

In the last few weeks, incidentally, in the hobby hours I was working on a patch for the AVR STK500 to be able to program the 'S8253, and I had to dig into avrdude too, so if you are willing to wait, I might come up with a solution for you maybe the next weekend.


List of 6 messages in thread
Using AT89ISP Cable With Ubuntu      Jon Wilder      01/08/12 12:41      
   AT89S8253 ISP      Jan Waclawek      01/08/12 15:05      
      AT89S8253 ISP      Jon Wilder      01/08/12 19:30      
         SUCCESS!!!      Jon Wilder      01/08/12 22:45      
            is your ware hard enough?      Jan Waclawek      01/09/12 06:36      
               What Jan means is a "solderless breadboard"      Richard Erlacher      01/09/12 08:44      

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