AR# 32847: 11.1 ISE/EDK - ERROR:NgdBuild:467 - output pad net 'fpga_0_ddr2_clk_0_OBUF' has an illegal buffer
AR# 32847
11.1 ISE/EDK - ERROR:NgdBuild:467 - output pad net 'fpga_0_ddr2_clk_0_OBUF' has an illegal buffer
Description
KEYWORDS: MPMC, double, NgdBuild:947, translate
When running Translate in the ISE tools, I receive several of the following errors:
ERROR:NgdBuild:467 - output pad net 'fpga_0_ddr2_clk_0_OBUF' has an illegal buffer ERROR:NgdBuild:467 - output pad net 'fpga_0_ddr2_clk_1_OBUF' has an illegal buffer...
ERROR:NgdBuild:947 - bidirect pad net 'fpga_0_ddr2_dq_0_OBUF' is driving non-input buffer(s): pin I on block fpga_0_ddr2_dq_0_OBUF with type OBUF ERROR:NgdBuild:947 - bidirect pad net 'fpga_0_ddr2_dq_10_OBUF' is driving non-input buffer(s): pin I on block fpga_0_ddr2_dq_10_OBUF with type OBUF...
Why do I see these errors, and how can they be resolved?
Solution
XST is adding a port/buffer to the MPMC IP Core which already contains buffers in the HDL source code.
In order to resolve this error, you will need to add the 'implementation' folder from your EDK design to the "Cores Search Directory" in the XST build options. This will ensure that the XST Read Cores option parses the 'implementation' folder of your EDK project to ensure that extra buffers will not be added to the MPMC IP Core.