question about 74HC299 operation

Discussion in 'Homework Help' started by eric_s88, May 9, 2011.

  1. eric_s88

    Thread Starter Member

    Apr 20, 2011
    157
    1
    Hi everyone!
    I have a problem in understanding pins operation in 74HC299 device.
    I have attached it here, I'm confused :confused: in the datasheet there is a MODE SELECT TABLE, and it is written that If we have a LOW signal on S0 and S1 pins its operation will be : Hold ( is this meaning that it would save digital data on input pins ? I/On ?? )
    and a HIGH signal on S0 and S1 will operate as: parallel load ( is this meaning that the saved data in the past mission will be apear ion I/On S pins?? ) and at last what about OE pins? what do they do exactly??
    I hope you get my mean right :(
    I have attached the datesheet , please read it ;)
    thank you
    Eric
     
  2. Georacer

    Moderator

    Nov 25, 2009
    5,142
    1,266
    On 00 Select, the output will hold and won't change its value regardless of its input.
    On 11 Select, the output will load the input in the next cycle, not asynchronously.

    Any HIGH input on the OE pins will disengage the output from its bus and it will present HIGH IMPEDANCE on its output.
    The same thing will happen on LOAD too.
     
  3. eric_s88

    Thread Starter Member

    Apr 20, 2011
    157
    1
    thank you buddy, I will try to do it ;)
     
  4. Georacer

    Moderator

    Nov 25, 2009
    5,142
    1,266
    It's all on the datasheet. You could have read that yourself instead of me.
     
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