— In this paper we propose a new method of test patterns compression based on a design of a dedicated SAT-based ATPG (Automatic Test Pattern Generator). This compression method is targeted to systems on chip (SoCs) provided with the P1500 test standard. The RESPIN architecture can be used for test patterns decompression. The main idea is based on finding the best overlap of test patterns during the test generation, unlike other methods, which are based on efficient overlapping of pre-generated test patterns. The proposed algorithm takes advantage of an implicit test representation as SAT problem instances. The results of test patterns compression obtained for standard ISCAS’85 and ‘89 benchmark circuits are shown and compared with competitive test compression methods.