# 6 bit output on 7 segment display

Discussion in 'Homework Help' started by pronoob, May 23, 2015.

1. ### pronoob Thread Starter New Member

May 23, 2015
5
0
hi,
i wanted to know how to display a random 6 bit output on 7 segment display? i have tried every where online but couldnt find any help. it would be really helpful if anyone can provide me with the circuit. Note: my work is solely restricted to IC's such as logic gates ,decoder,MUX,adder,subtractor,flip flops and counters.

thankyou.
p.s i have attached image of my circuit so far.its a 6 bit random number generator

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2. ### djsfantasi AAC Fanatic!

Apr 11, 2010
2,900
870
What do you want to show on the display? I hope you can use multiple displays, because 6 bits can represent over 1,000 different decimal values.

3. ### panic mode Senior Member

Oct 10, 2011
1,328
305
1000?

2^6=64

single 7-segment display can be used to display each of 6 bits individually (though you will have hard time interpreting display reading) or more reasonably display value as two digits...

4. ### djsfantasi AAC Fanatic!

Apr 11, 2010
2,900
870
Oops, I meant 64. Got lost counting binary places. I was doing the counting while riding in a car.

In any case, my point still stands as you also (more correctly) stated. More than a single 7 segment display is needed to more reasonably display the 64 values as two digits.

Otherwise, even six discrete LEDs would be easier to interpret than one 7 segment display.

5. ### MrCarlos Active Member

Jan 2, 2010
400
134
Hello pronoob

There are several methods to convert natural binary to BCD (Binary Code Decimal).

The method that I find easier is to use memory chips. Where you apply, THROUGH the Address BUS, your natural binary number and by the Data BUS you get numbers in BCD.
Only with this method you require a programmer Memory Chips.

Another method is to use a microcontroller, similar to the memory chip,
a microcontroller port you put the natural binary number. On the other port you get out the BCD number.
Usually it is written to the microcontroller a Lookup Table. Which is basically the decoder.
In this method a programmer for microcontrollers is required and to know programming.

00 to 09 do not add anything.
And so on.

This other method is very elaborate. They call shift left and add 3.
It is to move to the left all the BIT's natural binary number.
If the result is equal to or greater than 5, add 3 and shift to the left.
And so to end all BIT's natural binary number.
At the end we have the BCD.
(Note: I do not remember if indeed: when the result of shifted is equal to or greater than 5).

One method that I find interesting, is to use two types of counters: binary (0-F) and for decades (0-9).
The binary counter must be programmable and also able to count down. We program the natural binary We want to convert. Both counters are applied the same clock signal.
Then:
The binary counters are programmed.
We apply the clock signal to both types of Counters.
When the binary counter reaches zero stop the process.
In the decade counters we have the BCD number.

(X) = methods or circuits.

:

6. ### pronoob Thread Starter New Member

May 23, 2015
5
0
fellas!! i have 2 7 segment dislays and 2 7448 decoder ICs...but the problem im facing is that each decoder has 4 bit input and i have a 6 bit output.i have to provide inout in a way that the first digit is updated and the second digit also works when the output is greater than 9.

7. ### pronoob Thread Starter New Member

May 23, 2015
5
0
@MrCarlos thankyou.i think i can consider the option for adding multiples of 6. ...rest of the methods are very new to me as my course DLD is the basic level and i am not even a student of EE.

8. ### MrCarlos Active Member

Jan 2, 2010
400
134
Hello pronoob

I had not seen in detail the circuit shown in the image that you enclose your original message.
I see there are some things to improve.

May I ask you some questions ??
What is the purpose of the battery, switch, button ??
Note that if you close the switch when the X-OR gate, associate, has its output a low level may be damaged,

It is not wise, when you work with digital circuits, leaving floating inputs.
This is the case of the R and S inputs of the flip-flop's.
If you Don’t use them you must connect to VCC. in this case.

Good luck to develop your decoder, through adding multiples of 6 option.
The hard part is: how to detect what range is the random number of your counter, to add 6 or a multiple thereof.

9. ### crutschow Expert

Mar 14, 2008
13,475
3,361
I think the easiest approach with out using a micro or a ROM is the dual Binary-BCD counter approach since it requires no decision making logic.

10. ### pronoob Thread Starter New Member

May 23, 2015
5
0
the battery is to just enable the circuit once and then the switch will be turned off becuase the seeding would countinue through the feedback mechanism. the main idea is to provide 1 at the beginning. i would not be using an original battery.
Thankyou!

11. ### pronoob Thread Starter New Member

May 23, 2015
5
0
can you elaborate?

12. ### panic mode Senior Member

Oct 10, 2011
1,328
305
have you heard of leading zeroes? nothing stops you from expanding 6-bit to 8-bit and making two most significant bits zeroes. if you don't want hexadecimal display, you will need to add something like mentioned by crutschow to convert to BCD. there are different solutions depending on what is available or convenient:
http://en.wikipedia.org/wiki/Double_dabble

Last edited: May 24, 2015
13. ### crutschow Expert

Mar 14, 2008
13,475
3,361
Several of the methods described require testing of the binary word to determine whether it's above or below a certain value and that's a complex function to do if you aren't using a micro or other computer.
The counter method requires no such decision making.
Here's another discussion on the Binary-BCD conversion process.