Embedded systems are composed of a heterogeneous collection of digital, analog, and mixed-signal hardware components. This paper presents a method for the verification of systems composed of such a variety of components. This method utilizes a new model, timed hybrid Petri nets (THPN), to model these circuits. In particular, this paper describes an efficient, approximate algorithm to find the reachable states of a THPN model. Using this state space, desired properties specified in ACTL are verified. To demonstrate these methodologies, a few hybrid automata benchmarks, a tunnel diode oscillator, and a phase-locked loop are modeled and analyzed using THPNs.