HD74HC182 Datasheet | Hitachi Semiconductor

Description The HD74HC182 is a high-speed Carry Lockahead Generator. It is used with the HD74HC181 4-Bit Arithmetic Logic Unit to provide high-speed lockahead over World lengths of more than four bits. The device accepts up to four pairs of active-low Carry Propagate (P 0, P1, P 2, P 3) and Carry Generate (G0, G1, G 2, G3) signals and an active-high carries (C n+x, Cn+y, Cn+z) across four groups of binary adders. The HD74HC182 also has active-low Carry Propagate (P) and Carry Generate (G) outputs which may be used for further levels of lockahead. The logic equations provided at the outputs are: C n+x = Y0 (X0 + Cn) C n+y = Y1 {X 1 + Y0 (X0 + Cn)} C n+z = Y2 [X2 + Y1 {X 1 + Y0 (X0 + Cn)}] Y = Y3 (X3 + Y2) (X3 + X2 + Y1) (X3 + X2 + X1 + Y0) X = X3 + X2 + X1 + X0 or C n+x = G0 + P0Cn C n+y = G1 + P1G0 + P1P0C n C n+z = G2 + P2G1 + P2P1G0 + P2P1P 0C n G = G3 + P3G2 + P3P2G1 + P3P2P 1G0 P = P3P2P 1P 0 Also, the HD74HC182 can be used with binary ALUs in an active-low or active-high input operand mode. The connections to and from the ALU to the carry lookahead generator are identical in both cases. Features - - - - - High Speed Operation: tpd (Pn to P) = 11 ns typ (CL = 50 p F) High Output Current: Fanout of 10 LSTTL Loads Wide Operating Voltage: VCC = 2 to 6 V Low Input Current: 1 µA max Low Quiescent Supply Current: ICC (static) = 4 µA max (Ta = 25°C) Pin Designations Item G0, G1, G2, G3 P0, P1, P2, P3 Cn Cn+x, Cn+y, Cn+z G P VCC GND Pin No. 3, 1, 14, 5 4, 2, 15, 6 13 12, 11, 9 10 7 16 8 Functions Active-low carry generate inputs Active-low carry propagate inputs Carry input Carry outputs Active-low carry propagate output Active-low carry propagate output Supply voltage Ground Pin Arrangement G1 1 P1 2 C0 3 Inputs P0 4 G3 5 P3 6 Output P 7 P1 G0 P0 G3 P3 P G1 P2 G2 Cn Cn+x Cn+y G 16 VCC 15 P2 14 G2 13 Cn 12 Cn+x 11 Cn+y 10 G 9 Cn+z (Top view) Outputs Inputs Cn+z GND 8 Logic Diagram G P3 G3 Cn+z P2 G2 Cn+y P1 G1 P0 G0 Cn Cn+x HD74HC...