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Altera_Forum
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21 years ago

[Nios II]: questions on "trap" and modelsim

Hi, I started to use the "Nios II/fast core" and made some timing tests. but I got some trouble to find out how "trap" work. in assembly, when user issue a trap: .... tra...
Altera_Forum's avatar
Altera_Forum
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21 years ago

Sylvian,

The multiply/divide stuff is executed in our default handler as the result of an "unimplemenrted instruction" exception, something different from a user trap. We do this so that we can maintain binary compatibility between different versions of the Nios II core... so if some code is compiled to call a hardware multiplier that doesn't exist (as one example), the unimplmeneted insrtuction exception gets generated and we handle the multiply in software.