First of all, I'm asked to design a 4-bit calculator that accepts tow inputs which are in BCD and I have to convert them to Binary, so when i use the truth table the inputs and outputs will be identical because it is a 4-bit calculator.

should I get the logic diagram for BCD-to-Binary?,because the BCD and Binary numbers are the same in the digits for example 0001 in Binary is the as 0001 in BCD which is 1

Also,in logic work I used the ic 7447 to show the number in 7-segment as u can see here ( of course u should have logic work installed to open the following file)
http://www.zshare.net/download/827023905c043b91/
but it doesn't work I dont know why
sorry for that but I'm really really really confused
thank you

 

If you are supposed to do the arithmetic unctions in binary, then you will have to convert coming and going, so to speak.

I might remind you that 99 in BCD is not the same value in binary. Just as a hint, an input of 15 should become 1111 in binary.

Not everybody has Logic Work.

 

thank your for the fast response.
but i'm working on a 4-bit calculator with tow inputs and every inputs is 4-bits( for example 5+5 or 9+3 but I can't calculate 11+2 with the 4-bits calculator because 11 is more than 4 bits in BCD but the answer will be more than 4-bits for 9+3 which is ok)
,so I dont think that I can use the number 99 as an input which is more than 4 bits, am I right?
, so If I wanna convert from BCD to Binary I have to make a truth table with four inputs,but how many outputs?

 

bump
.............

 

BCD IS a binary code. It uses four bits to represent each digit in a base ten number. Binary uses as many bits as needed to represent a number in a base of 2.

http://en.wikipedia.org/wiki/Binary-coded_decimal read it for more info

 

thx
I wanna convert from BCD to Binary I have to make a truth table with four inputs,but how many outputs?

 

I wanna convert from BCD to Binary

BCD stands for Binary Coded Decimal. Notice the Binary part?

BDC goes from 0 - 9 using 4 bits, while the 4 bits in straight binary go from 0 - 15.

 

ok thx for your help
,so after I get the output in binary I need to convert it in BCD.
the output in binary will be 8 digits in BCD unless it was less or equal to 9( for example 3*9=27 and 27 is 0010 0111 in BCD)
so that means I create another truth table for Binary-to-BCD with 8 outputs?!!!!! that doesn't make sense!
sorry for my stupid questions but I'm really confused

 

Perhaps this section of our Ebook may help - http://www.allaboutcircuits.com/vol_4/chpt_1/5.html