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Altera_Forum's avatar
Altera_Forum
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8 years ago

connecting Nios ii system and other system over ram-controller with different clocks?

hello,

i plan a new project and i found a problem right at the beginning.

the plan is to connect an external computer over the gpio as adress- and databus to an fpga-board and use the board to do some calculations and then the external computer can access to the result.

so, I want to do the calculation with a nios ii system and have a little space in memory, where the external computer can place and get data for/from the nios ii.

the problem is, that the nios ii can run at 100 MHz, but the external system run's on a much slower clock. how can I connect this two systems?

maybe I only need a push in the right direction :-)

best regards,

peabrain

1 Reply

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    8 years ago

    You could create a shared memory: instantiate a dual port ram with port 1 connected to Nios data bus, while port 2 is exposed to the external system which must drive the data/address/control lines according to the avalon specifications.

    Then you should provide some sort of software handshaking for data transfer.