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???
04/19/06 14:44
Modified:
  04/19/06 14:47

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#114527 - nos and yes's
Responding to: ???'s previous message
I said:
you need no extra pin on the processor for the "Auto" option, it's still just Rx and Tx (and, of course, /PSEN and RESET)! The "extra" signals come from the PC's COM port...


Erik Malund said:
the "extra" signals still need to be connected to a pin


OK so once again, more slowly.
For ISP "hardware" entry, you need Rx, Tx, /PSEN and RESET.
The "autoISP" circuit connects to Rx, Tx, /PSEN and RESET.
The "manualISP" circuit connects to Rx, Tx; /PSEN is grounded via a switch or jumper manually and the chip is reset usually by a power cycle.
Using "NoTouch (C)Erik" you need Rx, Tx.
I see no significant difference in pin usage. I see no reason to spare /PSEN notabene RESET as a pin.

I said:
However, you still might need an A) emergency solution and also for the B) "first time" programming


Erik said:
A) "the backdoor" takes care of that.
B) a factory fresh chip IS in ISP mode


B is 100% true; however, the "backdoor" is no emergency solution. Emergency is, e.g. when someone @#$%s the programming so that the user program (nor backdoor then) runs correctly.

A pushbutton or two pins for a jumper hurt nothing.

Jan Waclawek

PS. Personal experience. I've just "locked up" a LPC932A1, NoTouch (C)Erik installed, just I made a tiny error during device programming, burning an incorrect file... Of course, no last resort (at least not a quick one), the chip in TSSOP soldered firmly down, only Rx and Tx leads to outer world... OK this is for hobby, can wait a moment in the drawer...


List of 16 messages in thread
TopicAuthorDate
AT89C51ED2 ISP Hardware configuration            01/01/70 00:00      
   from the source            01/01/70 00:00      
      I will try it.            01/01/70 00:00      
         because it would make datasheets books            01/01/70 00:00      
            family documents            01/01/70 00:00      
               Philips is good in this respect            01/01/70 00:00      
                  it's not philips            01/01/70 00:00      
         ISP circuit            01/01/70 00:00      
            Manual ISP            01/01/70 00:00      
               use NoTouch            01/01/70 00:00      
               handshake?            01/01/70 00:00      
                  yes'es and no's            01/01/70 00:00      
                     nos and yes's            01/01/70 00:00      
                        location dependent            01/01/70 00:00      
                           unlikely?            01/01/70 00:00      
                              make a .bat file            01/01/70 00:00      

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