This paper describes a mixed-platform framework dedicated to Dynamic Stability Assessment of power systems. DSA refers to tools capable of characterizing the dynamic stability of the system. Time domain simulation is critical for DSA analysis and is done by algorithms known as TD engines. In this work, operations are shared between a software platform and a hardware one. TD simulation is handled by a dedicated mixed-signal electronics implementation. Data flow control, user interfacing, configuration, result post-processing and other auxiliary operations are realized in software. This architecture combines the flexibility of the software with the high-performance of dedicated hardware. Results of a multi-contingency analysis and a critical clearing time determination analysis for sample test cases are presented. It is demonstrated that an increase in speed of almost three orders of magnitude can be achieved, compared to single-platform solutions.