CD40181BMS

The CD40181BMS 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 input M 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 logic mode, and addition, subtraction, decrement, left-shift and straight transfer in the arithmetic mode, according to the truth table. The CD40181BMS operation may be interpreted with either active-low or active-high data at the A and B word inputs and the function outputs F, by using the appropriate truth table.

The CD40181BMS 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 CD40181BMS. Use of the CD40182BMS look-ahead carry generator in conjunction with multiple CD40181BMS's permits high speed arithmetic operations on long words. A ripple carry output Cn+4 is available for use in systems where speed is not of primary importance.

Also included in the CD40181BMS 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 information in Table B.

The CD40181BMS is similar to industry types MC14581 and 74181.

The CD40181BMS is supplied in these 24-lead outline packages:

Braze Seal DIP ....HNZ
Ceramic Flatpack... H4P