As a system-level modelling language, SystemC possesses several novel features such as delayed notifications, notification cancelling, notification overriding and delta-cycle. It is challenging to formalise SystemC. In this paper, we study the denotational semantics for SystemC using
Unifying Theories of Programming
(abbreviated as UTP) . Two trace variables are introduced, one is to record the state behaviours and another is to record the event behaviours. The timed model is formalised in a three-dimensional structure. A set of algebraic laws is explored, which can be proved via the achieved denotational semantics.