Need help using 74191 up/down counter

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captinten2

Joined Dec 20, 2020
2
I'm trying to make a counter that counts down from 9 to 4 (9-8-7-6-5-4) then returns to 9 and so on. I managed to set the max to 9 but I don't know how to use the TC pin (pint 12) to set the minimum. Can anybody guide me on how to use the TC pin?
 

Papabravo

Joined Feb 24, 2006
21,159
TC indicates that the counter has all ones in the four stages. It is not relevant to your problem. In order to count down the D/U-bar pin must be tied high (to LOGIC 1) and you must load the value on the D-input when the output = 4
 
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