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4th May 2015, 11:05 #1
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If I have 12 bits each 4 represent a number in binary, how do i convert it to binary?
Hi,
How can I convert a 12 bit binary number where each 4 bits represent a character into an 8 bit binary number?
Example: 12 bit number : "001001000011" ==> 2,4,3 and I want to convert it to 243 ==> "11110011"
any help please?
What I did but still haven't reached a right answer:
Code VHDL  [expand] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59
signal output1, output2, output3 : integer range 0 to 9; signal output11, output22 : integer range 0 to 255; begin process(clk) begin if(clk'event and clk='1') then case input(11 downto 8) is when "0000" => output1 <= 0; when "0001" => output1 <= 1; when "0010" => output1 <= 2; when "0011" => output1 <= 3; when "0100" => output1 <= 4; when "0101" => output1 <= 5; when "0110" => output1 <= 6; when "0111" => output1 <= 7; when "1000" => output1 <= 8; when "1001" => output1 <= 9; when others => output1 <= 0; end case; case input(7 downto 4) is when "0000" => output2 <= 0; when "0001" => output2 <= 1; when "0010" => output2 <= 2; when "0011" => output2 <= 3; when "0100" => output2 <= 4; when "0101" => output2 <= 5; when "0110" => output2 <= 6; when "0111" => output2 <= 7; when "1000" => output2 <= 8; when "1001" => output2 <= 9; when others => output2 <= 0; end case; case input(3 downto 0) is when "0000" => output3 <= 0; when "0001" => output3 <= 1; when "0010" => output3 <= 2; when "0011" => output3 <= 3; when "0100" => output3 <= 4; when "0101" => output3 <= 5; when "0110" => output3 <= 6; when "0111" => output3 <= 7; when "1000" => output3 <= 8; when "1001" => output3 <= 9; when others => output3 <= 0; end case; end if; end process; output11 <= output1*100; output22 <= output2*10; finaloutput <= output1+output2+output3; output<= std_logic_vector(to_unsigned(finaloutput,8));
Last edited by FvM; 4th May 2015 at 11:13. Reason: Added syntax tags

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4th May 2015, 11:20 #2
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Re: If I have 12 bits each 4 represent a number in binary, how do i convert it to bin
What do you mean by "still haven't reached a right answer"? What are your requirements for a "right answer"?
Altough the BCD to binary operation can be described in less lines using ieee.numeric_std conversion functions, the shown code should basically work.

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4th May 2015, 11:23 #3
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Re: If I have 12 bits each 4 represent a number in binary, how do i convert it to bin
Yes I know, I tried using the conversion function but it didn't work so I used the long conversion.
I don't have a specific criteria, It's just that after I use a test bench I don't get the correct answer.

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4th May 2015, 12:10 #4
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Re: If I have 12 bits each 4 represent a number in binary, how do i convert it to bin
It's just that after I use a test bench I don't get the correct answer.

4th May 2015, 19:15 #5
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Re: If I have 12 bits each 4 represent a number in binary, how do i convert it to bin
you are looking for a BCD to binary converter. Try this code:
http://vhdlguru.blogspot.in/2015/04/...onversion.htmlIf we admit that human life can be ruled by reason, then all possibility of life is destroyed.

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4th May 2015, 19:25 #6
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Re: If I have 12 bits each 4 represent a number in binary, how do i convert it to bin
The only issue I see with the OP's code is the range of output1 should be restricted to 0,1, or 2 as the range of the result for output11 can not be outside the range of 0 to 255. Perhaps the range restrictions are the root of the problem.

4th May 2015, 22:12 #7
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Re: If I have 12 bits each 4 represent a number in binary, how do i convert it to bin
Perhaps the range restrictions are the root of the problem.
A simulator stops with an error when the overflow occurs.
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