General Description: I/O buffer macros (ibuf 4,8,16; obuf 4,8,16; and obufe 4,8,16) give one of the following errors or warnings:
ERROR:NgdBuild:455 - logical net 'xxx' has multiple drivers WARNING:NgdBuild:463 - input pad net 'xxx has an illegal input buffer ERROR:NgdBuild:466 - input pad net 'xxx' has illegal connection ERROR:NgdBuild:467 - output pad net 'xxx' has an illegal buffer
Solution
1
Use multiple instances of single-buffer primitives instead of buffer macros.
To determine if a library element is a macro or a primitive, refer to the Libraries Guide on support.xilinx.com.
2
Use individual primitives (ibuf, obuf, obufe) instead of the bulk buffers.