August Revised April Synchronous 4-Bit Binary Counters. General Description.
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Can someone tell me what is use of that pins in counter? Scroll to continue with content. Papabravo Joined Feb 24, 13, I don't have my datsheet handy it is packed away in preparation for a move , but ENT and ENT pins are used to enable counting.
They are useful in designing state machines where you need to "hold the present state" until a specified condition occurs. Look at the truth table for details. Hello, Have a look at page 11 of the attached datasheet. GopherT Joined Nov 23, 8, RCO is ripple-carry-output. It allows the chip to trigger a second chip to count how many times this one rolls over from 15 back to 0 - that way, you can cascade multiple chips and make it an 8, 12 or 16 bit counter or more. Not used if only 0 to 15 is needed.
It goes high on the 15th pulse and stays high until the roll-over pulse that causes the output to zero. The LS chip is synchronous - when the clear pin is LOW when a clock pulse goes low to high, the outputs clear - if the enable P ENP pin is High, the output will increment with each clock tick if clear is not low. Hello I looked that page. This counter do two things, increments or load the new value.
I think when counter in increments mode the input should be following Code:. Don't mix the two values sets. It can get confusing. Papabravo said:. I think preset usually means to set the counter to all 1's, but I don't see a way to do that or do what you want unless you explicitly load a particular starting value. If you do a preset to 6, the counter will go 6,7,8, As you can see in the internal diagram, the counter has only one set of flipflops that are used to hold the count, so there is no way it could remember that you want it to allways start beginning with 6.
Last edited: Sep 16, I am looking LTspice model file for 74ls counter. Someone can tell me where to get LTspice model file for 74ls It works fine. Just pull everything high except ground pin and outputs pins and apply a clock to pin 1 And it will count away.
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74ls163 counter need help
74LS163 Datasheet PDF