VLSI and SPICE modeling of ALU

The Arithmetic and Logic Unit （ALU） is a combination circuit that performs a number of arithmetic and logical operations within a microprocessor. The demand for faster and compact ALUs makes it desirable to test the ALU in conjunction with pre-design parts prior to manufacture. This may be accomplished in a process using CAD and SPICE simulation software. Our purpose is to realize a method for importing a layout drawn in Tanner L-edit and simulated in T-Spice into PSpice which is referred to as software talking. To do so we use an eight-function instruction set called Complimentary Metal Oxide Semiconductor Arithmetic and Logic Unit （CMOS ALU） which is laid out in Tanner L-edit and produces an extracted net-list which is simulated in T-Spice. An ALU equivalent design is then modeled in PSpice for further testing with pre-manufactured parts of the PSpice library.