Forum Discussion

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

Cyclone III Active Serial Configuration

Does anyone know how long it will take to configure a EP3C10 with a EPCS1 using the active serial (AS) configuration? I need the FPGA to be live around 300 ms after power-up, and wanted to know if this is feasible.

Thanks for any response.

4 Replies

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

    I know one of my EP3C25 designs takes approximatly 150 ms after power-up for configuration in active serial mode. (Fast Active Serial Mode I believe)..

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

    Have a look at this document (http://www.altera.com/literature/hb/cyc3/cyc3_ciii51016.pdf).

    You need to take into account the POR time (you'll probably have to use a fast POR, but then, be sure that your power supplies will reach the correct level in time), then you have the configuration itself (page 9-20 gives you a method to estimate the maximum configuration time) and finally the initialization (pages 9-9/9-10) before the FPGA goes into user mode.
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    14 years ago

    --- Quote Start ---

    You need to take into account the POR time (you'll probably have to use a fast POR, but then, be sure that your power supplies will reach the correct level in time), then you have the configuration itself (page 9-20 gives you a method to estimate the maximum configuration time) and finally the initialization (pages 9-9/9-10) before the FPGA goes into user mode.

    --- Quote End ---

    Why would you be concerned that the power supplies are at the correct levels? Won't the FPGA start the POR time (3ms-9ms for Fast POR) once the power supplies have reached their correct levels?
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    14 years ago

    The POR starts when the main power supplies (VccInt, VccA, and the VccIO for the banks that contain configuration pins) reach a certain level (I tried to find those levels, but I can't see them anywhere in the datasheet). Then you have the POR delay to ensure that those power supplies stabilize within the specified range (+/- 5% usually).