# basic question aboout counter

Joined Nov 24, 2011
712
I know we can make counter, memory, registers with the help of d flip flop
first I want learn the basic concept of counter how to make counter with the help of d flip fliop
I want to count only four 1234 number i know i need display, d flip one d flip flop store one bit. but don't know how many flip flop are i need to make counter does any circuit i need to use like adder, encoder i don't want to explain whole process I just want how to make counter after learn about the flip flop

#### t06afre

Joined May 11, 2009
5,934
To make a asynchronous counter is good place to start with counters. Just Google the term asynchronous counter. And you will get a lot of info. Then feel free to ask if you are stuck. You can also get some ideas by looking at common counter ICs like the 74ls163 74hc4040

#### tshuck

Joined Oct 18, 2012
3,534
Also, don't forget about the ebook here.

Also, if you are going for synchronous counters, this addendum should help clarify the section on the matter.

#### MrChips

Joined Oct 2, 2009
21,300
You need to learn the difference between straight binary counter and binary coded decimal (BCD) counter.

Four bits will allow you to count from 0 to 15 using straight binary.

You will also need four bits to count from 0 to 9 using BCD.

For multiple digits, the choice is yours. Binary or BCD is simpler or more difficult depending on the specific application.

#### ian field

Joined Oct 27, 2012
6,539
To make a asynchronous counter is good place to start with counters. Just Google the term asynchronous counter. And you will get a lot of info. Then feel free to ask if you are stuck. You can also get some ideas by looking at common counter ICs like the 74ls163 74hc4040
The easiest way of all is to use a standard off the shelf BCD decade counter and decode for a reset at one after the required count.

My brain might not be firing on all cylinders this close to Christmas - but I think you can just as easily use a 4-bit binary counter, as you never reach the illegal codes.

The old favourite for a BCD counter was the 7490, but AFAIK that's discontinued - it was replaced by the 74390 (2 counters in 1 package).

Joined Nov 24, 2011
712
thanks for useful information
type of counter
Ring counter
BCD counter
up/down counter
I have some question about counter
1) can we make ring counter,BCD counter, up/down counter only with D flip flop or SR flip flop or T flip flop or Jk flip flop
2)IF i want to count 2 numbers how many flip flop i need to count 2 or I want to count 3 numbers how many flip flop i need to use

#### ScottWang

Joined Aug 23, 2012
6,909
You don't need to know all of counters in a short time, you just focus on what you want to learn at the present time, the BCD and binary counter are the more useful counter in the daily life and in the digital world and uC area.

You can using one CD4013 to build two bits counters, it is counting from 0,1,2,3, you just need to make each D Flip-Flop as divider by 2 and cascading them.

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#### ian field

Joined Oct 27, 2012
6,539
thanks for useful information
type of counter
Ring counter
BCD counter
up/down counter
I have some question about counter
1) can we make ring counter,BCD counter, up/down counter only with D flip flop or SR flip flop or T flip flop or Jk flip flop
2)IF i want to count 2 numbers how many flip flop i need to count 2 or I want to count 3 numbers how many flip flop i need to use
It might be worth your while studying some of the databooks/application manuals floating about on the web.

Archive.org is an excellent source - search first for signetics, they have a very detailed MSI applications manual that shows the internal logic of various types of counter, its for an obscure and long extinct logic family, but its the principle of operation you're after.

Texas Instruments have published some superb applications manuals that include their 7400 family counters in some detail.

When I raided archive.com I remember using the term "databook", and got a fair haul of ebooks, but I don't remember whether the application manuals turned up with more detailed ferreting around.