2 Replies Latest reply on Oct 7, 2015 11:49 PM by Madhu Lakshmipathy

    USB boot with alternate PID

    hilmar.koch

      In our newly developed board, the FX3 bootloader enumerates as VID/PID = 0x04B4/00BC. We found that our PMODE setting is 111 instead of F11 (This was caused by connecting PMODE[2] to an FPGA input that has an internal pullup that can't be turned off before configuration).

         

      The question is: Is this behavior documented somewhere ? Having a different PID is perfectly fine, but the tables in the programming manual don't list the combination PMODE[2:0] = 111.

         

      On the other hand, I did find the PID=0x00BC mentioned in AN76405 on page 10 (4.3.8). The document says
      "The bootloader may boot with VID=0x04B4/PID=0x00BC or VID=0x04B4/PID=0x0053 based on the setting of the PMODE pins", but gives no hint of how to set PMODE[2:0] to use this feature.

         

      Is there another manual that clarifies this beahavour ? Can we leave the board design as it is or do we risk that it won't work with future revisions of the FX3? Which is the PMODE setting to use 0x04B4/0053 ?