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Altera_Forum's avatar
Altera_Forum
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11 years ago

Accessing EPCS Controller through an avalon MM-Bridge

Hi,

I'm working on a project with 3 NIOS and i'm trying to implement a boot from EPCS for each of those NIOS.

I have one "Top Level" Qsys with 3 subsystem QSYS containing Nios CPU.

My EPCS Flash Controller is located in this Top Level Qsys and each Nios is connected to this controller through an avalon MM Bridge.

Data and instruction Port are connected on this bridge but i can't access to EPCS with nios2-flash-controller. I get the no EPCS register found error.

Do anyone know if EPCS Flash Controller must be connected directly to Data And Instruction Port of a NIOS Cpu or if i'm missing something?

PS: At start up only one NIOS is working, 2 remaining NIOS are in reset state

Thanks for your help !

2 Replies

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

    You have to ensure that only one of the nios is accessing the epcs at any one time.

    (that may, or may not, be related the to problem you are seeing)
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    11 years ago

    Hi,

    I worked on it and I forgot to connect jtag_module_reset to the epcs_controller. Now EPCS is detected succesfully !

    Thanks for your help