How to load 74hc192 with a number

Thread Starter

O_0

Joined Jun 3, 2017
5
Hello,
I wanted to ask on how can I load a number in 74hc192 ? I'm doing a counter circuit with three digits, so I have a counter for each digit, however, it starts from zero and sometimes random numbers. How can I get the counter to start from 9 ? Thank you.
 

djsfantasi

Joined Apr 11, 2010
7,830
Have you read the datasheet? Can you describe for us what PL, P0, P1, P2 & P3 are?

What are you using the 74HC192 for in the big picture?
 

WBahn

Joined Mar 31, 2012
26,398
Hello,
I wanted to ask on how can I load a number in 74hc192 ? I'm doing a counter circuit with three digits, so I have a counter for each digit, however, it starts from zero and sometimes random numbers. How can I get the counter to start from 9 ? Thank you.
Please post a schematic of how you are using the counter so that we can look for the cause of the random numbers -- there are a few possible reasons.
 

GopherT

Joined Nov 23, 2012
8,012
Hello,
I wanted to ask on how can I load a number in 74hc192 ? I'm doing a counter circuit with three digits, so I have a counter for each digit, however, it starts from zero and sometimes random numbers. How can I get the counter to start from 9 ? Thank you.
Use pins P0,P1,P2, P3 to set the binary value of 9.
Then the value of the output will be set to 9 when the Parallel Load (PL) pin goes from Hi to Lo.
 

Thread Starter

O_0

Joined Jun 3, 2017
5
Have you read the datasheet? Can you describe for us what PL, P0, P1, P2 & P3 are?

What are you using the 74HC192 for in the big picture?
I did read the data sheet. PO, P1, P2, P3 are the inputs of the counter, I usually don't use those so they are connected to ground. PL is the parallel load, where I can load the counter with a value, I tried connecting logic gates AND to get the value 1001 and the output was inserted in the load but nothing happened.
I think I can add it in the inputs, can't I ?
 

GopherT

Joined Nov 23, 2012
8,012
I did read the data sheet. PO, P1, P2, P3 are the inputs of the counter, I usually don't use those so they are connected to ground. PL is the parallel load, where I can load the counter with a value, I tried connecting logic gates AND to get the value 1001 and the output was inserted in the load but nothing happened.
I think I can add it in the inputs, can't I ?
You may not normally use them but they are required if you want a preset value. You can simply pull P0 and P3 to High. Then use some logic to trigger a pulse to the PL pin to load the preset value when you want a 9 on the output.
 

Thread Starter

O_0

Joined Jun 3, 2017
5
You may not normally use them but they are required if you want a preset value. You can simply pull P0 and P3 to High. Then use some logic to trigger a pulse to the PL pin to load the preset value when you want a 9 on the output.
How can I trigger a pulse ? Can I do that with a push button instead of the clock signal ?
 

GopherT

Joined Nov 23, 2012
8,012
How can I trigger a pulse ? Can I do that with a push button instead of the clock signal ?
Yes, a push button works fine. Make sure you use a pull-up resistor to keep a 5v signal on the PL pin until the button is pressed to ground the pin. Google "pull up resistor" if needed.
 

Thread Starter

O_0

Joined Jun 3, 2017
5
Yes, a push button works fine. Make sure you use a pull-up resistor to keep a 5v signal on the PL pin until the button is pressed to ground the pin. Google "pull up resistor" if needed.
Yeah, I've used those plenty of times. Thank you for you help.
 
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