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Burst Counter Operation and chip disabled for synchronous dual port SRAM's

Burst Counter Operation and chip disabled for synchronous dual port SRAM's

Anonymous
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Question: If I do a read or write of a number of words and I use the internal counter (ie load the counter start address on the first word and then count after that), but I only give a CE (chip enable) every other clock; will I read data from consecutive address locations every other clock?  An example: For a burst read -- first clock load counter, second clock do nothing, third clock give chip enable and read first data, fourth clock do nothing, fifth clock give chip enable and read second data (next one in memory after first), sixth clock do nothing, seventh clock give chip enable and read third data, etc.  Note that output enable and counter enable will always be active. Could you confirm this for me?

 

Answer:

The counter advances based upon the rising edge of clock and not CE0# nor CE1, so in this example, assuming a free running clock:

 

                                                                                                                                                                                         
   

     Clock cycle

  
   

     Operation

  
   

     ADS#

  
   

     CNTEN#

  
   

     Internal Counter value

  
   

     1st

  
   

     Load counter

  
   

     low

  
   

     low

  
   

     --

  
   

     2nd

  
   

     Do nothing

  
   

     high

  
   

     low

  
   

     address

  
   

     3rd

  
   

     Read

  
   

     high

  
   

     low

  
   

     address +1

  
   

     4th

  
   

     Do nothing

  
   

     high

  
   

     low

  
   

     address +2

  
   

     5th

  
   

     Read

  
   

     high

  
   

     low

  
   

     address +3

  
   

     6th

  
   

     Do nothing

  
   

     high

  
   

     low

  
   

     address +4

  

As the table above shows, you end up reading out every other word.

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