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Altera_Forum's avatar
Altera_Forum
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16 years ago

SignalTap offloading time difference in the same fix (linux vs windows)

I have compared SignalTap offloaiding time for Windows XP and Ubuntu (linux)

Windows XP: ~2 sec

Ubuntu (linux): ~40 sec

Quartus 9.0 sp1

Ubuntu x32 vs Windows XP

Altera USB download cable

I see working LED on the Altera USB blaster during all offloading time.

Why we have this large delay on the same .stp?

What difference in Ubuntu linux?

Thank you.

2 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    16 years ago

    I guess, the performance difference is due to USB driver operation. I'm aware of similar effects with Windows applications that are operating the USB I/O in an inappropriate way. As long as the driver has no configurable settings (as the original Windows FTDI drivers have for FIFO latency), you have probably no option to influence the USB Blaster performance. Except for reporting to Altera support and hope for a change.

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

    --- Quote Start ---

    I guess, the performance difference is due to USB driver operation. I'm aware of similar effects with Windows applications that are operating the USB I/O in an inappropriate way. As long as the driver has no configurable settings (as the original Windows FTDI drivers have for FIFO latency), you have probably no option to influence the USB Blaster performance. Except for reporting to Altera support and hope for a change.

    --- Quote End ---

    But I have received such answer:

    He uses Slackware linux (usb-bb2 by libusb). And he didn't have any timing problem with SignalTap.

    What difference between this Linux distributives?