Designing a mixed-signal integrated hardware requires the mixed simulation for legacy digital blocks and analog circuits, which are usually represented by the Verilog description language for digital blocks and the SPICE circuit netlist of analog circuits. Without model translations or source-level modifications and to simulate mixed legacy Verilog models and SPICE circuit netlists that are usually developed based on the different SPICE languages, parameters and primitives, this paper proposes a simulation framework whose concept is connecting a legacy Verilog and proper SPICE simulator for the target SPICE model using a run-time infrastructure (RTI) based on high level architecture (HLA) and adapters that are pluggable libraries to enable the interoperation and integration of simulators through HLA. For the interoperation, to exchange analog/digital signals, the adapter converts analog/digital signals to events or events to analog/digital signals using user-defined, signal-event converters. To synchronize different time advance policies, the adapter performs time synchronization procedures based on the pre-simulation concept. For the integration of Verilog/SPICE simulators and the RTI, adapters are developed following each component interface, which are IEEE-std Verilog procedural interface, proposed SPICE procedural interface and IEEE-std HLA interface. The proposed framework was applied to the digitally controlled buck converter simulation.