M54HC182

The M54/74HC182 is a high speed CMOS FUNCTION LOOK AHEAD CARRY GENERATOR fabricated in silicon gate C²MOS technology. It has the same high speed performance of LSTTL combined with true CMOS low power consumption. These circuit are capable of anticipating a carry across four binary adders or group of adders. They are cascadable to perform full look-ahead across nbit adders. Carry, generate-carry, and propagate-carry functions are provided as shown in the pin connection table. When used in conjunction with the HC181 arithmetic logic unit, these generators provide high-speed carry look-ahead capability for any word length. Each HC182 generates the look-ahead (anticipated carry) across a group of four ALU's and, in addition, other carry ookahead circuits may be employed to anticipate carry across sections of four look-ahead packages up to n-bits. The method of cascading circuits to perform multi-level look-ahead is illustrated under typical application data.

Carry input and output of the ALUs M54/74HC182 are in their true form, and the carry propagate (P) and carry generate (G) are in negated form ; therefore, the carry functions (inputs, outputs, generate, and propagate) of the look-ahead generators are implemented in the compatible forms for direct connection to the ALU. Reinterpretation of carry functions as explained on theHC181 data sheet are alsoapplicable to and compatible with the look-ahead generator. All inputs are equipped with protection circuits against static discharge and transient excess voltage.