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???
07/04/05 13:45
Modified:
  07/04/05 13:50
Read: times


 		 #96515 - Modifications...
Responding to: ???'s previous message
Abhishek said:
please let us know what modification you have made if you wish.


Hallo Abhishek,

the circuit of atmel's ISP-'cable' you will find here:

http://www.atmel.com/dyn/resou...p_C_v5.PDF

Phillip has posted this link in another thread.

I add 10µF Tantal and 150R resistor from Vcc to ground. This in order to guarantee that supply voltage of target (AT89S52 to be programmed) falls down to negligible potential, if the target's supply is switched-off.
At the target I add 4k7 pull-up resistor to reset line.

The meaning of these extra parts is the following:
As I do not want to have target's supply voltage rise and fall without activated reset line, I connect and disconnect the target to ISP-'cable' with target's supply voltage switched-off. So, after starting windows 2000 on my older laptop, I connect ISP-'cable' to printer port of laptop, then connect it to target, with its supply voltage switched-off. Then I switch-on target's supply voltage and programm the chip. At the end, I switch-off target's supply voltage again. Then, I disconnect target from ISP-'cable', with the ISP-'cable' still sitting in printer port of laptop.

This procedure guarantees, that with each target's supply voltage rise or fall the reset line of AT89S52 is active, means high. This makes corruption of flash code memory very very unprobable.

Kai


List of 54 messages in thread
TopicAuthorDate
Unale to Program the AT89S52 TQPF in sys            01/01/70 00:00      
   cable seems too long            01/01/70 00:00      
      Cable ?            01/01/70 00:00      
      Crosstalk?            01/01/70 00:00      
         me too and same result            01/01/70 00:00      
            Modifications...            01/01/70 00:00      
               Tank you very much Kai            01/01/70 00:00      
         my hesitance            01/01/70 00:00      
      Problem Solved :)            01/01/70 00:00      
         Bah,            01/01/70 00:00      
            Wow !            01/01/70 00:00      
            i suspected that....            01/01/70 00:00      
   Coul someone send mo ISP_Programer30a            01/01/70 00:00      
      if you took the time to read            01/01/70 00:00      
         He is asking about ISP            01/01/70 00:00      
            if you need a programmer, you are not do            01/01/70 00:00      
               depends what you call a programmer            01/01/70 00:00      
                  standard signals            01/01/70 00:00      
                     The moon is...            01/01/70 00:00      
                        nice point ;)            01/01/70 00:00      
                        last I looked            01/01/70 00:00      
                           Programmers vs cables            01/01/70 00:00      
                              all is relative            01/01/70 00:00      
                                 Kitchen table programmers            01/01/70 00:00      
                                    additionally            01/01/70 00:00      
                                 SPI-ISP vs UART-ISP            01/01/70 00:00      
                                    bit bang and one button            01/01/70 00:00      
                                       programmer            01/01/70 00:00      
                                          no technician needed            01/01/70 00:00      
                                             was the PDA/laptop free?            01/01/70 00:00      
                                                yes, the PDA/laptop was free            01/01/70 00:00      
                                                   I have seen boxes for configuration            01/01/70 00:00      
                                                      free or "cost you nothing"            01/01/70 00:00      
                                                         summary?            01/01/70 00:00      
                                                            sure            01/01/70 00:00      
                                                Neat            01/01/70 00:00      
                                                   Thanks            01/01/70 00:00      
                                    I agree with this            01/01/70 00:00      
                                       ISP is more straighforward            01/01/70 00:00      
                                          hardware is no garantee            01/01/70 00:00      
                                             sure            01/01/70 00:00      
                                                Not so sure            01/01/70 00:00      
                                                   ISP: SPI vs UART continued...            01/01/70 00:00      
                                                      True but...            01/01/70 00:00      
                                                         I know of none            01/01/70 00:00      
                                                            Do you mean            01/01/70 00:00      
                                                               re kicking and screaming            01/01/70 00:00      
                                                               issues...            01/01/70 00:00      
                                                                  Still sounds like entering ISP problem            01/01/70 00:00      
                                                                     my lengthy posts are boring            01/01/70 00:00      
                                                                     entry of ISP            01/01/70 00:00      
                                                                        alternative UART-ISP entry            01/01/70 00:00      
                                    Kitchenware is what isn't thorougly deve            01/01/70 00:00      
                                       somehow the UART method has escaped all            01/01/70 00:00      

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