Mixed-signal design and test tools are failing to keep apace with the increasing necessity for design exploration at the e arly stages.We outline a methodolo gy and toolset to enable test selection at the early design stages by providing a high level fault simulator and associatedblocklevel modeling and traversal capabilities. Experimental results show that the outlined methodolo gy pr ovides superior fault simulation speed-ups while helping to minimize the test time for a mixed-signal receiver system.