MM54HC181/MM74HC181 Arithmetic Logic Units/Function Generators General Description These arithmetic logic units (ALU)/function generators utilize advanced silicon-gate CMOS technology. They possess the high noise immunity and low power consumption of standard CMOS integrated circuits, as well as the ability to drive 10 LS-TTL loads. The MM54HC181/MM74HC181 are arithmetic logic unit (ALU)/function generators that have a complexity of 75 equivalent gates on a monolithic chip. These circuits perform 16 binary arithmetic operations on two 4-bit words as shown in Tables 1 and 2. These operations are selected by the four function-select lines (S0, S1, S2, S3) and include addition, subtraction, decrement, and straight transfer. When performing arithmetic manipulations, the internal carries must be enabled by applying a low-level voltage to the mode control input (M). A full carry look-ahead scheme is made available in these devices for fast, simultaneous carry generation by means of two cascade-outputs (pins 15 and 17) for the four bits in the package. When used in conjunction with the MM54HC182 or MM74HC182, full carry lookahead circuits, high-speed arithmetic operations can be performed. The method of cascading HC182 circuits with these ALU's to provide multi-level full carry look-ahead is illustrated under typical applications data for the MM54HC182/ MM74HC182. If high speed is not of importance, a ripple-carry input (Cn) and a ripple-carry output (Cna4) are available. However, the ripple-carry delay has also been minimized so that arithmetic manipulations for small word lengths can be performed without external circuitry. Features Y Full look-ahead for high-speed operations on long words Y Arithmetic operating modes: Addition Subtraction Shift operand a one position magnitude comparison Plus twelve other arithmetic operations Y Logic function modes: Exclusive-OR Comparator AND, NAND, OR, NOR Plus ten other logic operations Y Wide operating voltage range: 2V±6V Y Low input current: 1 mA maximum Y Low quiescent current: 80 mA maximum