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???
02/24/03 18:51
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#39941 - RE: 8255
Responding to: ???'s previous message
Better yes,,,go to the FAQ section / Hardware and read the info there about re-designing away from the 82c55 use. Simpler curcuit will be easier to use and easier to debug. One chip type that is prettu cool for adding outputs to a microcontroller is a device called an 8 bit addressable latch. A part number would be 74HC259. Here is a link to the data sheet for the Toshiba 74HC259.

These are cool becasue you can individually access each bit. When you wire these usually the A-B-C inputs go to address lines and the D input goes to a data line. It is however to also hook the D input to an address line.
For example if hookup was...
A3 -> 'hc259.C
A2 -> 'hc259.B
A1 -> 'hc259.A
A0 -> 'hc259.Din
Then a write to address+0 will clear the bit and a write to address+1 will set the bit.

Michael Karas


List of 16 messages in thread
TopicAuthorDate
8255            01/01/70 00:00      
   RE: 8255            01/01/70 00:00      
      RE: 8255            01/01/70 00:00      
         RE: 8255            01/01/70 00:00      
   RE: 8255            01/01/70 00:00      
      RE: 8255            01/01/70 00:00      
   RE: 8255            01/01/70 00:00      
   RE: 8255            01/01/70 00:00      
   RE: 8255            01/01/70 00:00      
      RE: 8255 / the Diodes            01/01/70 00:00      
      RE: 8255            01/01/70 00:00      
         RE:40xx I<sup>2</sup>C            01/01/70 00:00      
            RE: RE:40xx I<sup>2</sup>C            01/01/70 00:00      
               RE: RE:40xx I<sup>2</sup>C            01/01/70 00:00      
   RE: 8255            01/01/70 00:00      
   RE: 8255            01/01/70 00:00      

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