Looking at some of the improvements over Spartan®-3A, Spartan-6 FPGAs offer twice the capabilities with half the power by offering: dual-register 6-input LUT (look-up-table) logic structure, integrated PCI Express endpoint blocks, access rates of up to 800 Mbps using integrated memory controllers, low-power 250 MHz DSP48A1 slices with 18 x 18 multipliers, clock management tiles, each consisting of two DCMs and one PLL, and eight low power 3.2 Gbps GTP serial transceivers.