nonverter to BCD

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justas12

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hi, i need to make a circuit, where 7-segments bin code is converted to bcd code, using CMOS.And circuit shoud have EI (enable input). I really need help.please
 
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hi, i need to make a circuit, where 7-segments bin code is converted to bcd code, using CMOS.And circuit shoud have EI (enable input). I really need help.please

hi,
Look for a 74C915 datasheet, it old.
 
yes it is work for my studies. i don't have what to show now, because i dont know how to start this job. is there any algorithm to make meaning table?
 
yes it is work for my studies. i don't have what to show now, because i dont know how to start this job. is there any algorithm to make meaning table?

hi,
The 7 segments of a display are 'named' a,b,c,d,e,f,g.
The 'a' seg is the top segment, then counting clockwise b,c,d,e,f.... the g seg is the centre segment.

So write out 10 columns of 7 segments showing when the seg is lit as a '1' and not lit as a '0'.

So start your columns at column "0" BCD
this one will be the BCD number zero "0", the next column will be "1" and so on.
Code:
    "0"  "1"   "2"  "3" ... so on to "9"
a   1     0
b   1     1
c   1     1
d   1     0
e   1     0
f   1     0
g   0     0

Do you follow this part, so far.?
 
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but 7segments binary code, have 128 meanings.am i right?.....2^7=128...

hi,
It is not binary, if it was you would be correct.

Its a 7 segment code, look at these images.

OK.?

EDIT: are you confusing 'segments' with 'bits'.???
 

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hi,
OR is this what you are trying to do.
 

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i need to do this:

input output
1 0000001 to 0001
......... ...............
128 1000000 to 0001 0010 1000
 
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hi,
So its the last block diagram I posted: 7 bit binary to 3 digit BCD conversion.

When you said segments in your first post I read it as a 7 segment [LED display] to BCD... they used to make an ic to do just that.!

Have you SEARCHED this forum for binary to BCD .?

EDIT: this is one thread asking the same question.
https://www.electro-tech-online.com/threads/binary-to-bcd-converter.38418/
 
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yes i read forum...and i need to this using logic elements...shoud i write all 128 binary meanings? what should i do next?
 
yes i read forum...and i need to this using logic elements...shoud i write all 128 binary meanings? what should i do next?

hi,
You will find using simple logic elements that configuring a 7 bit binary to 3 digit BCD is quite difficult.
I dont think you writing all the 0 to 127 binary/bcd's will be helpful.

Who has set you this problem.?

Look thru this link.
**broken link removed**
 
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i saw this algorithm yesterday...but i didn't understant how does it works.. maybe, because of my bad english..can you a little explain and i will try to make similiar table..?
 
i cant use microcontroler, because my task is tu make circuit using CMOS.

hi,
What you have to do is to make 7 of the "C" modules, all the "C" modules are exactly the same. See image #1.
Look at the module truth table, this is the logic block you have to design, its not easy.

When you have the 7 "C" modules connect them as image #2.
 

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