Article ID: 000085843 Content Type: Error Messages Last Reviewed: 08/29/2013

Error: GXB Central Control Units <Transceiver 1> and <Transceiver 2> cannot have the same starting channel number <number>

Environment

  • Quartus® II Subscription Edition
  • BUILT IN - ARTICLE INTRO SECOND COMPONENT
    Description

    This error message is generated in the Quartus® II software  when designs targeting Stratix® IV GX devices contain transceiver instances configured in Basic (PMA Direct) mode utilizing a CMU PLL.

    The Quatus II software incorrectly requires extra logical channel addresses for the CMU PLL. To workaround this problem , reserve 4 additional logical channel addresses for all Basic (PMA Direct) instances that use a CMU PLL. 

    For example, this error is generated in the following transceiver configuration: An instance called Inst1 has two channels and uses Basic (PMA Direct) mode. Instance Inst2 has two channels and uses Basic mode, which uses the PCS block in the transceiver.

    To avoid the error, follow these steps:

    1. Set Inst1 to have a starting channel number of 0.
      • The logical channel addresses 0 and 4 are then allocated to the two channels of Inst1.
    2. Reserve logical channel address 8: Do not use this address.
    3. For the second instance (Inst2), set the starting channel number to 12.
    4. Set the Number of channels in the ALTGX_RECONFIG controller megafunction to the nearest multiple of 4 from the highest logical channel address.
      • In this example, set the Number of channels to 16.
    5. When connecting the reconfig_fromgxb bus of the ALTGX_RECONFIG controller, connect the bits corresponding to the reserved address to ‘0’. 
      •  In this example, the ALTGX_RECONFIG controller provides 4*([16:0]) bits. Connect the reconfig_fromgxb bus of the ALTGX_RECONFIG controller and the ALTGX transceiver instances as follows:
        • reconfig_fromgxb[33:0] of the ALTGX_RECONFIG instance – reconfig_fromgxb[33:0] of inst1
        • reconfig_fromgxb[50:34] of the ALTGX_RECONFIG instance – 17’h00000
        • reconfig_fromgxb[67:51] of the ALTGX_RECONFIG instance – reconfig_fromgxb[17:0] of inst2

    Note that this issue occurs only for transceiver instances in Basic (PMA Direct) modes using CMU PLLs. If the ATX PLL is used for Basic (PMA Direct) modes, follow the starting channel numbering scheme documented in the Stratix IV Dynamic Reconfiguration (PDF) chapter in the Stratix IV GX Handbook.

    Related Products

    This article applies to 2 products

    Stratix® IV GX FPGA
    Stratix® IV GT FPGA