MC14581B

Features:

• Functional and Pinout Equivalent to 74181.
• Diode Protection on All Inputs
• All Outputs Buffered
• Supply Voltage Range = 3.0 Vdc to 18 Vdc
• Capable of Driving Two Lowpower TTL Loads or One Lowpower Schottky TTL Load over the Rated Temperature Range

Pinout




Specifications




Description

The MC14581B is a CMOS 4bit ALU capable of providing 16 functions of two Boolean variables and 16 binary arithmetic operations on two 14bit words. The level of the mode control input determines whether the output function is logic or arithmetic. The desired logic function is selected by applying the appropriate binary word to the select inputs (S0 thru S3) with the mode control input high, while the desired arithmetic operation of MC14581B is selected by applying a low voltage to the mode control input, the required level to carry in, and the appropriate word to the select inputs. The word inputs and function outputs can be operated with either active high or activ e low data. Carry propagate (P) and carry generate (G) outputs of MC14581B are provided to allow a full lookahead carry scheme for fast simultaneous carry generation for the four bits in the package. Fast arithmetic operations on long words are obtainable by using the MC14582B as a second order look ahead block. An inverted ripple carry input (Cn) and a ripple carry output (Cn+4) are included for ripple through operation. When the device is in the subtract mode (LHHL), comparison of two 4bit words present at the A and B inputs is provided using the A = B output. MC14581B assumes a highlevel state when indicating equality. Also, when the ALU is in the subtract mode the Cn+4 output can be used to indicate relative magnitude as shown in this table