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???
04/14/08 14:08
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 		 #153254 - I used a 74LS121 and...
Responding to: ???'s previous message
It worked!! :D
Thanks a lot to all the members of this board who helped me in this!

However I have two questions:

1. Will not adding the 74LS121 increase the current drawn and thereby increase the power consumption and offset any benefit I would have got by going to power down mode?

I plan to measure the current drawn in normal and PD mode and then find out the average current to really decide whether I would eventually deploy the 121.

2. My code looks something like this:

Save This Code
     ORG 0003H          ;ISR for /INT0
     LCALL INT0_ISR
     RETI

     ORG 0030H  
MAIN:                    ;main line code
     ;some code...
     ;still more code...
     ;still some more code...
HERE: MOV PCON,#02H      ;going to power down mode
      SJMP HERE

INT0_ISR:                 ;ISR for my interrupt
       ;do stuff
       ;do more stuff  
       RET




Is this correct? I mean is the method of continuously running in a loop and setting the micro to PD mode correct?

The above code works though but I want to be very sure before going ahead with deploying my 121.

regards,
Seemanta




List of 42 messages in thread
TopicAuthorDate
Problem waking up from power down mode:AT89S52            01/01/70 00:00      
   Have you seen the pulse?            01/01/70 00:00      
      Saw tthat            01/01/70 00:00      
         I agree!            01/01/70 00:00      
      monoflop IC number?            01/01/70 00:00      
         also know as one shot (in the foot)            01/01/70 00:00      
            Supervisor chip?            01/01/70 00:00      
               try digikey            01/01/70 00:00      
                  Can you explain how that would help?            01/01/70 00:00      
         how about 4538?            01/01/70 00:00      
         You can, but also read this...            01/01/70 00:00      
      Maybe rather than a monoflop....            01/01/70 00:00      
         Ehem...            01/01/70 00:00      
            Ehem....Hmmm            01/01/70 00:00      
               Why messy?            01/01/70 00:00      
               Remember that the oscillator is turned off            01/01/70 00:00      
                  So using a one-shot seems the best idea..right?            01/01/70 00:00      
                     a one shot should always ...            01/01/70 00:00      
                        I tried using an RC circuit...but it did not work            01/01/70 00:00      
                           sorry, I was wrong            01/01/70 00:00      
                              If one shot is a close second...            01/01/70 00:00      
                                 I'd rather not            01/01/70 00:00      
                                    but problem with FF is that            01/01/70 00:00      
                                       ah, Arghmel            01/01/70 00:00      
                           Not same part            01/01/70 00:00      
                     If You Use PCF8563 RTC...            01/01/70 00:00      
                        555 vs '121? Which is better?            01/01/70 00:00      
                           121 ..            01/01/70 00:00      
                              I used a 74LS121 and...            01/01/70 00:00      
                                 yes it will, but            01/01/70 00:00      
                                    HC and HCT?            01/01/70 00:00      
                                       there is this fancy newfangled thing ....            01/01/70 00:00      
                                    There is no 74HC121, but HC123 and HC221            01/01/70 00:00      
                                 Should really consider....            01/01/70 00:00      
                                    I really would consider PCF8563 but...            01/01/70 00:00      
                           Digital pulse is still better            01/01/70 00:00      
                     I would try this            01/01/70 00:00      
                        elegant, but why ....            01/01/70 00:00      
                           You can, of course, but...            01/01/70 00:00      
                              reg power consumtption...            01/01/70 00:00      
                                 Have you seen my circuit?            01/01/70 00:00      
                                    Pulse Mode from RTC,,,,            01/01/70 00:00      

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