The ATU18 series of ULCs are fully suited for conversion of latest CPLDs and FPGAs. It supports within one ULC 55Kbits to 847Kbits DPRAM and 45Kgates to 1000 Kgates. Typically, ULC die size is 50% smaller than the equivalent FPGA. Metal level customisation allows a DPRAM blocks compatibility with Xilinx or Altera blocks. Devices are implemented in highperformance 0.18 um CMOS technology to improve the design frequency and reach 250Mhz typical application and local clock up to 400Mhz. The architecture of the ATU18 series is dedicated for efficient conversion of latest CPLD and FPGA device types with higher IO count. A compact RAM cell and a large number of available gates allow the implementation of memories compatible with FPGA RAM, as well as JTAG boundaryscan and scanpath testing. Conversion to the ATU18 series of ULC provides a significant reduction of the operating power when compared to the original PLD or FPGA. The ATU18 series has a very low standby consumption, less than 0.145 nA/gate typically at commercial temperature. Operating consumption is a strict function of clock frequency, which typically results in a significant power reduction depending on the device being compared. For a NAND2 cell the dynamic power consumption is 0.124uW/MHz at 1.8V.