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Altera_Forum
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15 years ago

Nios II custom instruction faster in 32bit or 128bit

Hi all, Will the NIOS II run faster processing 128bit data using 128-bit custom instruction or 32bit custom instruction and run 4 times? Since NIOS II is 32-bit processor. Thanks..
Altera_Forum's avatar
Altera_Forum
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15 years ago

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Combinatorial custom instructions are passed input data for EVERY instruction cycle, the output value will be used if the instruction decode indicates that it is required (this is how all the ALU instructions work).

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I'm not very understand... As i pass my 32-bit input to the combinatorial custom instruction, the result will be retrieve after a clock cycle and the program will proceed. Isn't that so? Why you saying that "input data for EVERY instruction cycle"?

Thanks..