The problem of custom instruction

Altera_Forum · ‎01-21-2010

I want to define instruction of multiplication,but there is a problem that I cann't solve.

the code is:

library ieee;

use ieee.std_logic_1164.all;

use ieee.std_logic_unsigned.all;

use ieee.std_logic_arith.all;

entity mult is

port(dataa:in std_logic_vector(31 downto 0);

datab:in std_logic_vector(31 downto 0);

result:out std_logic_vector(31 downto 0);

reset:in std_logic:='0';

start:in std_logic:='0';

clk_en:in std_logic:='0';

clk:in std_logic);

end mult;

architecture behave of mult is

signal rt:std_logic_vector(31 downto 0);

begin

rt<=dataa(15 downto 0) * datab(15 downto 0);

result<=rt;

end behave;

please help me!

thanks in advance!

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Altera_Forum · ‎01-21-2010

What's the issue you are running into?

Here is an example you can look at:

http://www.altera.com/literature/ug/ug_nios2_custom_instruction.pdf

http://www.altera.com/literature/ug/ug_custom_instruction_files.zip

Altera_Forum · ‎01-22-2010

thank you for your suggestion,I will read it carefully.

Altera_Forum · ‎01-22-2010

I am sorrow,I use the code that you give me to implement CRC custom instruction,but there is a same problem that I cann't solve.

I did all step by step follow the PDF,but when I select the CRC from the library on the life side panel of the Custrom Instruction tab,and click the ADD to add it to the Nios Processor,the error appears.

thank you.

http://b31.photo.store.qq.com/http_imgload.cgi?/rurl4_b=b579f8b54f494fc69149a5de70a1aee9158b4942fcdec056a28ce16f00afb29d8e64c3094609d5fcf27982de47cf11496e9e2e7eb30094ad8a1a95eb1f5db610f2e13eb99eb611d43f6b679363d86885849605cb&a=32&b=31