&

VLSI3 VLSI: 14

: 03108797

: 03110818

4bit, .

CMOS08.1. :

ABCSUMBorrow

00000

00111

01011

01101

10010

10100

11000

11111

, C , SUM o A-B Borrow . :

SUM = R[XOR(A, B), C) = ABC + ABC + ABC + ABC Borrow = C [XOR(A, B)] + A B = ABC + ABC + AB : :

. 1150ps.

: P = 0.574mW2. 4 bit 4 bit 16 FA.

4 bit .

FAB : 4bit : 7 3 , :1011Y3Y2Y1Y0

X1001X3X2X1X0

1011

0000

0000

1011

001100011P8P7P6P5P4P3P2P1P0

4bit: P = 23.87 mW P = 13.12 mW P = 10.66 mW

2 .