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Altera_Forum's avatar
Altera_Forum
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14 years ago

HELP:how to remove these timing critical warning

I get some critical warnings for timing,when I make the TSE project.

I want to implement a 150MHz nios II system of TSE transciever,

and I almost finish the hardware of nios II with the DE4 board.

but I get the critical warnings,how to solve it ,help me please.thank you so much

..

I attach the quartus II archive file,Please help me as your convenience!

the Qsys componets like:

CPU-->

-->onchip memory

-->pipeline bridge 1----> cpu peripherals

-->pipeline bridge 2----> IOs

-->pipeline bridge 3----> ext_flash

-->TSE_MAC

-->SGDMA-tx/rx

-->descriptor memory

thanks again!!

3 Replies

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

    Look for the top failing paths report in Timequest to determine where you need to add more pipelining.

    A typical path that needs a pipeline bridge is the one between the Nios CPU masters (data and instruction) and the CPU's JTAG debug slave interface.

    Going over 100MHz on a Nios II system on a Cyclone FPGA is possible, but requires some patience...
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    14 years ago

    first thanks for your help.

    yes I place a pipeline bridge between cpu and jtag. as :

    cpu <----->pipeline bridge <---->[jtag uart,sysid,timer,..]

    but these critical warning are for the TSE. so it is a little complicated

    and difficult to me.

    --- Quote Start ---

    Look for the top failing paths report in Timequest to determine where you need to add more pipelining.

    A typical path that needs a pipeline bridge is the one between the Nios CPU masters (data and instruction) and the CPU's JTAG debug slave interface.

    Going over 100MHz on a Nios II system on a Cyclone FPGA is possible, but requires some patience...

    --- Quote End ---

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

    You should look at the top failing paths instead. It is in the "Macros" category in Timequest.

    If the failing paths are inside the TSE itself, then there isn't a lot you can do, except decreasing the frequency. If it is between the TSE and something else, then there may be something you can do.