The problem of cyclic scheduling for specialized processors systems is pre- sented and a worst case analysis of a heuristic scheduling algorithm is studied. A resource constrained cyclic scheduling problem is characterized by k, the number of types of functional units employed, mx the maximal number of processors of the same type and ± the maximal precedence delay. The main problem is to cope with both precedence and resource constraints which make the problem NP-complete in general. A guaranteed approach, called decomposed software pipelining, has been proposed by Gasperoni and Schwiegelshohn, followed by the retiming method by Calland, Darte and Robert to solve the problem for parallel processors. We present, in this paper, an extension of this approach to resource-constrained cyclic scheduling problems with precedence delays and we provide an approximation algorithm. Let ¸ and ¸opt be respectively the period given by the algorithm and the optimal period. We establish an approximation bound.