Answers Database

PPR 5.0: PPR Error 9062: Global Buffer Driven by IO, IBUF


Record #311

Problem Title:
PPR 5.0: PPR Error 9062: Global Buffer Driven by IO, IBUF


Problem Description:



Solution 1:




PPR reports:
    *** PPR: ERROR 9062:
	  The global buffer '$1I3' (type=BUFGP, output signal=$1N18) is driven
	  by I/O '$1I2' (type=IBUF, connected to pad '$1N22_pad'). The BUFGP
	  input must be routed through a dedicated path that does NOT pass
	  through the normal input buffer. Routing this signal through an IBUF
	  would incur significant routing delay and would require an additional
	  IOB.

WHY THIS HAPPENS

To make users aware of the fact that primary global buffers require the
use of an IO pin, situations where a BUFGP is fed from a non-IPAD symbol
gererate warnings and/or errors.  When internal logic drives a BUFGP, PPR
gives warning 9010.  When a BUFGP is fed from an IBUF, warning 9010 and
error 9062 (shown above) are generated.

WHAT TO DO:

As the message states, either add a LOC to the IPAD, or remove the IBUF.




End of Record #311