HD74HC182

HD74HC182 Look-Ahead Carry Generator REJ03D0586-0300 Rev.3.00 Jan 31, 2006 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 (P0, P1, P2, P3) and Carry Generate (G0, G1, G2, G3) signals and an active-high carries (Cn+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: Cn+x = Y0 (X0 + Cn) Cn+y = Y1 {X1 + Y0 (X0 + Cn)} Cn+z = Y2 [X2 + Y1 {X1 + Y0 (X0 + Cn)}] Y = Y3 (X3 + Y2) (X3 + X2 + Y1) (X3 + X2 + X1 + Y0) X = X3 + X2 + X1 + X0 or Cn+x = G0 + P0Cn Cn+y = G1 + P1G0 + P1P0Cn Cn+z = G2 + P2G1 + P2P1G0 + P2P1P0Cn G = G3 + P3G2 + P3P2G1 + P3P2P1G0 P = P3P2P1P0 Also, the HD74HC182 can be used w...