AR# 44529


MIG 7 Series v1.3 DDR3 - Incorrect MAP Parameters when CKE and ODT Are Allocated to a Byte Group Separate from the Remaining Address/Control Signals (ERROR:Route:471)


The MIG v1.3 DDR3 SDRAM design generates the MAP parameters incorrectly when CKE and ODT are allocated to a byte group separate from the remaining address/control signals leading to routing failures during implementation. This issue only occurs when the Debug option is enabled in the MIG tool.This occurs because the routing tools are trying to place debug logic in the CKE/ODT byte group slices. The implementation tools error with a message similar to the following:

"ERROR:Route:471 -
This design is unrouteable. Router will not continue. To evaluate the problem please use fpga_editor. The nets listed below can not be routed:
Unrouteable Net:u_mig_7series_v1_3/u_memc_ui_top_std/mem_intfc0/ddr_phy_top0/u_ddr_mc_phy_wrapper/u_ddr_mc_phy/ddr_phy_4lanes_0.ddr_phy_4lanes/phy_encalib<1>
Unrouteable Net:u_mig_7series_v1_3/u_memc_ui_top_std/mem_intfc0/ddr_phy_top0/u_ddr_mc_phy_wrapper/u_ddr_mc_phy/ddr_phy_4lanes_0.ddr_phy_4lanes/phy_encalib<0>
Unrouteable Net:u_mig_7series_v1_3/u_memc_ui_top_std/mem_intfc0/ddr_phy_top0/u_ddr_mc_phy_wrapper/u_ddr_mc_phy/ddr_phy_4lanes_0.ddr_phy_4lanes/ddr_byte_lane_B.ddr_byte_lane_B/po_rd_enable
Unrouteable Net:u_mig_7series_v1_3/u_memc_ui_top_std/mem_intfc0/ddr_phy_top0/u_ddr_mc_phy_wrapper/u_ddr_mc_phy/ddr_phy_4lanes_0.ddr_phy_4lanes/phaser_ctl_bus<1>"


To work around this issue,you need to change the BYTE_LANES_Bx parameter from '1' to '0' for the byte lane in which CKE and ODT are allocated.

As an example, data byte groups are allocated in Bank #34 and Address in Bank #33 (T0, T1 are allocated for Address and Control signals and in T2 only CKE and ODT are allocated). In this case, MIG generates BYTE_LANES_B1 parameter with the value as 4'b1110. This parameter needs to change to 4'b1100.

Linked Answer Records

Master Answer Records

Answer Number Answer Title Version Found Version Resolved
43099 MIG 7 Series v1.3 - Release Notes and Known Issues for ISE Design Suite 13.3 N/A N/A
AR# 44529
Date 05/22/2012
Status Active
Type Known Issues
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