I need help "digital clock"

[satellite5005]

Hi! I need to design a combinational circuit that will display the time on a standard digital clock. The design should be abler to display correctly the 4digit time using the usual 12-hour format
Where can I get this information?

 

[John Sorensen]

At about a million places on the net. Have you tried Googling it?

j.

 

[udi_hakim]

How complex and accurate do you want your clock to be?

you can use a chip called RTC - Real Time Clock.
The best RTC i know is the DS12c887, it has a battary, crystal and UV RAM inside but you need some kind of uC or uP to read and write to it.

Or you can use a simple counters and a crystal to make you clock.

 

[ljcox]

Also search this forum. Others have been doing the same or similar designs

Len

 

[John Sorensen]

Your request says you need to do a combinational circuit (i.e. gates) while your signature says you need to use flip-flops (i.e. sequential). What, exactly, is the requirement of your project (obviously a homework assignment because no one would do this for kicks)?

The most straight forward way would be to use an oscillator: a crystal will have the best stability. A divider (because crystals oscillate way too fast). Some counters (74HC393s), LED display drivers (7447 or similar), and some gates to reset the counters at the right time and increment the other counters.

If it has to be purely combinational, you'll end up making sequential elements out of gates, which would be a nightmare.

j.

 

[ljcox]

You need to design some Modulo 6, Modulo 10 and Modulo 12 counters.

The attached is part of a Modulo 6 design using JKs. I'll leave you to complete it.

Len