Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
12 years ago

custom instruction

Hello world; I have created my first custom IP for matrix multiplication, and i want to access it using a custom instruction, how can I make this?, my IP is compatible with the avalon bus interfac...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
12 years ago

All you have to do is add another interface to your existing custom IP, with the new interface being a custom instruction slave. e.g. one custom instruction slave interface, and one or more Avalon interfaces for loading/storing your matrix.

Then simply glue the opcodes to your desired behavior of your existing IP. The only real trick is that you need to be careful with cache coherency (since your existing Avalon interfaces will not being going through the NIOS cache, if you have one).