	US 7,490,305 B2
	Method for driving values to DC adjusted/untimed nets to identify timing problems
Robert B. Gass, Pflugerville, Tex. (US); Yee Ja, Round Rock, Tex. (US); and Christoph Jaeschke, Tuebingen (Germany)
Assigned to International Business Machines Corporation, Armonk, N.Y. (US)
Filed on Jul. 17, 2006, as Appl. No. 11/457,865.
Prior Publication US 2008/0016480 A1, Jan. 17, 2008
Int. Cl. G06F 17/50 (2006.01)

U.S. Cl. 716—4 [716/5; 716/6]

18 Claims

1. A method, in a data processing device, for verifying an operation of untimed net segments of an integrated circuit design, comprising:

receiving the integrated circuit design;

receiving a “don't care” (DC) adjusted list that identifies net segments that do not need to adhere to timing requirements;

comparing entries in the DC adjusted list to a netlist for the integrated circuit design to identify an untimed net segment based on a match of a net segment in the DC adjusted list with a net in the netlist for the integrated circuit design;

driving a value along a pathway to the at least one untimed net segment;

monitoring an output state value from the untimed net segment;

verifying an operation of the untimed net segment of the integrated circuit design based on the collected output value from the untimed net segment;

determining whether there is a violation in the operation of the untimed net segment;

determining whether downstream logic in the integrated circuit design uses the output value; and

removing the untimed net segment from the DC adjusted list if there is a violation in the operation of the untimed net segment and downstream logic in the integrated circuit design does not use the output value.