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Altera_Forum
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13 years ago

New IP development

Hello, I am interested in developing some instructions which can do the bignum operations (like adding two operands of 1024 bit) and hence by plan to implement a simple Full Adder like this: ...
Altera_Forum's avatar
Altera_Forum
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13 years ago

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Akhil>> What do you mean by a custom instruction interface? Is it an interface to fetch the corresponding operand (+, - ,..) from the NIOS II? If so how to do

that from my IP module? (please note that passing those 1024 bits may not be a good idea if we have to take 32 clock cycles to do that)

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See this document: http://www.altera.com/literature/ug/ug_nios2_custom_instruction.pdf

and this example: http://www.altera.com/support/examples/nios2/exm-custom-instruction.html

You do not pass the 1024-bit operands through this interface. You supply register references and those 32-bit registers would contain the address locations in RAM of where the 1024-bit operands are located. See Figure 2-1 of the .pdf.