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David Prentice
01/11/12 13:11
  01/11/12 13:16

Read: 493 times

#185436 - The AT89ISP will expect active-high RESET
Responding to: ???'s previous message
You obviously have a PC with an LPT port !!

The Atmel cable will expect active-high RESET. The software will control it as necessary. You will have a pull-down resistor on the RESET line for the device to run when there is no programmer connected. The Atmel software expects one and only one cable configuration.

There are several software apps for programming the AT89S8253.
You do not have to use the Atmel software.
Most software can be configured for the AT89ISP cable. e.g. any LPT pin, any polarity.

IME the AT89S8253 crystal oscillator is very fussy. Follow the app notes to the letter.
Every other MCU I have ever come across oscillates reliably even with not-exact components.

I would guess that you come from PIC16Fxxx chips. An 8051 is a lot more pleasant architecture.
However, the PIC peripherals are miles better than bog-standard 8051 peripherals. (the exception: AT89S8253 has an SPI TX buffer)


List of 7 messages in thread
AT89ISP Reset Pin Issue      Jon Wilder      01/11/12 12:02      
   If you want a positive-going RESET ...      Richard Erlacher      01/11/12 13:10      
      no, you can't        Erik Malund      01/11/12 13:21      
         You can do it, though you may not want to      Richard Erlacher      01/11/12 23:35      
   The AT89ISP will expect active-high RESET      David Prentice      01/11/12 13:11      
   Try to run the initialize target command...      Kai Klaas      01/11/12 17:13      
      By the way...      Kai Klaas      01/12/12 07:57      

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