An apparatus, method and 
computer program product are provided for performing a sequence of 
verification tests to perform hardware and 
software co-
verification on a 
system under 
verification. The apparatus comprises a plurality of 
signal interface controllers operable to be coupled to the 
system under verification, with each 
signal interface controller being operable to perform one or more test actions transferring at least one of one or more stimulus signals and one or more response signals between a corresponding portion of the 
system under verification and the 
signal interface controller during performance of the sequence of verification tests. A 
debugger is also provided which is operable to control operation of a 
processing unit associated with the system under verification, the 
processing unit being operable to execute 
software routines. A 
debugger signal interface controller is arranged to interface with the 
debugger and to perform one or more test actions transferring at least one of one or more stimulus signals and one or more response signals between the debugger and the debugger signal interface controller during performance of the sequence of verification tests. A test manager coupled to the plurality of signal interface controllers and the debugger signal interface controller is operable to transfer test controlling messages to these interface controllers identifying the test actions to be performed. By this approach, the test manager is operable to control the operation of the 
processing unit via the debugger signal interface controller and the debugger in order to co-ordinate the execution of the 
software routines with a sequence of verification tests. This has been found to be a particularly efficient technique for performing hardware and software co-verification.