Instructables

Circuit for 8 bit number to BCD?

For a TTL project I'm working on, I wanted to have 7 segment display output for the 8 bit numbers it works with. After searching on google and not finding very well documented circuits, I decided to ask here. Because the input is 8 bit, it should output 3 numbers. I only need the circuit to do the BCD because I can use 7 segment display drivers from there. (Like a 7446 IC) Thank you.

lets see you want a 256 count counter is that right?

Joe
Super_Nerd (author)  Josehf Murchison12 months ago
Well, actually it's an output for a combinational logic circuit
They have hundreds on the net just Google "combinational logic circuit" and pic a TTL circuit and expand it to fit your needs.
Super_Nerd (author)  Josehf Murchison12 months ago
I did search Google for the converter circuit, but couldn't find a well documented one.
Google "frequency counter circuits"
and then "clock circuits"
They use the same circuits to make frequency counters and clocks.
Super_Nerd (author)  Josehf Murchison11 months ago
Thank you for your help, but I find out how one of the circuits I looked at before worked.
AndyGadget12 months ago
 
Do you have access to programmable ROM?
It would be easy to generate a look-up table using 2 x 8bit wide ROMS to convert your 8 bits into 12 bits out for the display drivers.
Super_Nerd (author)  AndyGadget12 months ago
No I do not, but good idea nonetheless.
+1 for brilliant sneakiness....
mpilchfamily12 months ago
Look into micro controllers like the Arduino
Super_Nerd (author)  mpilchfamily12 months ago
I don't want to use micro controllers for this, I'd rather use 7400 logic gates.
iceng12 months ago
Is this 8 bit number actually
eight individual lines 0 to 111111112 = 3778 = 25510 = FFh ?
or is it just four individual lines 0 to 11112  = 178 = 1510 = Fh ?

A
Super_Nerd (author)  iceng12 months ago
By 8 bit, I mean an 8 bit number (0-255) not 8 bit BCD.