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???
09/11/11 22:22
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#183711 - For Software Controlled Strobing...
Responding to: ???'s previous message
Erik Malund said:
In particular when the microcontroller is a SiLabs type the I/Os can be set to push-pull and the communications to the display works well. fine, if you do not need bi-directional comms, which I have always needed.


If you are using software controlled strobing to a peripheral and the MCU is the single master controller you can still use push-pull during outputs and write data. When you get ready to do a read type operation you simply put the port mode register back to input mode for those signal lines that will be driven by the peripheral during the read pulse. After the read strobe the port mode can be put back to push-pull output.

Indeed you have to do it this way anyway for MCUs that are non-8051 and lacking the ability to support quasi-bidirectional I/O pins.

-------------------
Side Bar Comment:

I was reading some information about the newer Atmel AT89LP series of single clocker parts and find that on those parts the I/O pins come up by default as strict inputs. If one desires the support for the legacy style quasi-bidirectional pins one has to program port mode registers to act that way intentionally. It seems, from an Atmel WhitePaper, that this must be done as a means of putting the part into the lowest power mode out of reset.

Michael Karas



List of 42 messages in thread
TopicAuthorDate
LCD for 3V system            01/01/70 00:00      
   digikey            01/01/70 00:00      
      Thanks            01/01/70 00:00      
         mouser            01/01/70 00:00      
         re digikey            01/01/70 00:00      
          it's a pain to buy through them in the UK            01/01/70 00:00      
            VAT            01/01/70 00:00      
               VAT            01/01/70 00:00      
                  VAT            01/01/70 00:00      
   This any good?            01/01/70 00:00      
      Different results???            01/01/70 00:00      
         Try...            01/01/70 00:00      
            Comes up with 14 results for me            01/01/70 00:00      
   5V LCD on 3V System            01/01/70 00:00      
      Let me add.....            01/01/70 00:00      
         if it's a hobby project...            01/01/70 00:00      
      fine, if you do not            01/01/70 00:00      
         For Software Controlled Strobing...            01/01/70 00:00      
      No 5V rail            01/01/70 00:00      
      No 5V rail            01/01/70 00:00      
         I do not know if ...            01/01/70 00:00      
            Wonderful            01/01/70 00:00      
               how about this            01/01/70 00:00      
                  Slow but huge matrix display?            01/01/70 00:00      
                     Infernoptix            01/01/70 00:00      
                        That looks fun!            01/01/70 00:00      
            Battery powered, not even a backlight            01/01/70 00:00      
               have they got the lifetime reasonable by now            01/01/70 00:00      
                  You can do way better than that.            01/01/70 00:00      
                     Big improvement            01/01/70 00:00      
                        Per, can we have a link to a datasheet, please            01/01/70 00:00      
                           What's 'a typical lifetime'            01/01/70 00:00      
                              grabbing an example            01/01/70 00:00      
                                 But this all settles back to ....            01/01/70 00:00      
                                 All depends on needs            01/01/70 00:00      
                                    not my experience            01/01/70 00:00      
                                       Side by Side            01/01/70 00:00      
                                          observations            01/01/70 00:00      
                                             You need side-by-side comparison or instruments for 10%            01/01/70 00:00      
                                                I think I got it            01/01/70 00:00      
                                                   Did you compare used/unused segments?            01/01/70 00:00      
                                       Intensity loss depends on designed 100% intensity            01/01/70 00:00      

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