HCC40181B

The HCC40181B (extended temperature range) and HCF40181B (intermediate temperature range) are monolithic integrated circuits, available in 24-lead dual in-line plastic or ceramic package and plastic micro package. The HCC/HCF40181B is a low-power four-bit parallel arithmetic logic unit (ALU) capable of providing 16 binary arithmetic operations on two four-bit words and 16 logical functions of two Boolean variables. The mode control inputM selects logical (M = High) or arithmetic (M = Low) operation. The four select inputs (S0, S1, S2, and S3) select the desired logical or arithmetic functions, which include AND, OR,NAND,NOR, and exclusive- OR and-NOR in the logical mode, and addition, subtraction, decrement, left-shift and straight transfer in the arithmetic mode, according to the truth table. The operation may be interpreted with either active-low or activehigh data at the AandBword inputs and the function outputs F, by using the appropriate truth table. It contains logic for full look-ahead carry operation for fast carry generation using the carry-generate and carry-propagate outputs G and P for the four bits of the HCC/HCF40181B. Use of the HCC/HCF40182B look-ahead carry generator in conjunction with multiple HCC/HCF40181B's permits high-speed arithmetic operations on long words. Aripple carry output Cn+4 is available for use in systems where speed is not of primary importance. Also included in the HCC/HCF40181B is a comparator output A = B, which assumes a high level whenever the two four-bit input words A and B are equal and the device is in the subtract mode. In addition, relative magnitude information may be derived from the carry-in input Cn and ripple carryout output Cn + 4 by placing the unit in the subtract mode and externally decoding using the informatio in table II. It is similar to industry types MC 14581 and 74181.