The use of these boards for validating the design gave rise to a width restriction related to the communication bus, since the Nexys2 board has a 40 I/O pin expansion bus. Consequently, generation of the different bitstreams for both the FMother and the FUT Board were affected by this restriction. A limitation was also encountered in the FUT 's PowerPC area,which was solved by restricting design conditions in the CLB test modules (Table 1).