TEST BANK FOR CMOS VLSI DESIGN A Circuits and Systems Perspective 3rd Ed By Neil H.E. Weste

Solutions
1
Note: solutions to simulation exercises are not included. Chapter 12 is not yet complete,
and a few other solutions are presently missing. DH 8/4/04
Chapter 1
1.1 Starting with 42,000,000 transistors in 2000 and doubling every 26 months for 10
years gives transistors.
1.2 Some recent data includes:
Table 1: Microprocessor transistor counts
Date CPU Transistors (millions)
3/22/93 Pentium 3.1
10/1/95 Pentium Pro 5.5
5/7/97 Pentium II 7.5
2/26/99 Pentium III 9.5
10/25/99 Pentium III 28
11/20/00 Pentium 4 42
8/27/01 Pentium 4 55
2/2/04 Pentium 4 HT 125
42M 2
10 × 12
26
è ---------------- ø
æ ö
· » 1B
2 SOLUTIONS
The transistor counts double approximately every 24 months.
1.3
1.4
1
10
100
1990 1995 2000 2005
Year
Transistors (Millions)
A
B
C
D
Y
A
B
Y
C
D
D
A B C
A
B
C
D
D
A B
C
Y
A B
C
C
A B
B
A
A
B
(c)
Y
(a) (b)
CHAPTER 1 SOLUTIONS 3
1.5
1.6
(a) A Y
A
B
Y
(b)
A
B
Y
(c)
(d)
A
C
B
Y
Y
B B
C C
B
A A
C C
B B B
A A
4 SOLUTIONS
1.7
1.8
1.9 The minimum area is 5 tracks by 5 tracks (40 l x 40 l = 1600 l2).
1.10 The layout is 40 l x 40 l if minimum separation to adjacent metal is considered,
exactly as the track count estimated.
A1A1A0A0
Y0
Y1
Y2
Y3
(a)
Y1
Y0
A0
A1
A1
A0
A2
(b)
A
VDD
GND
B C
Y
D
CHAPTER 1 SOLUTIONS 5
1.11
1.12 5 tracks wide by 6 tracks tall, or 1920 l2.
1.13 This latch is nearly identical save that the inverter and transmission gate feedback
has been replaced by a tristate feedaback gate.
n+ n+
p substrate
p+ p+
n well
A
Y VDD
n+
GND
B
D Y
CLK
CLK
CLK
CLK
6 SOLUTIONS
1.14
(c) 4 x 6 tracks = 32 l x 48 l = 1536 l2.
(e) The layout size matches the stick diagram.
1.15
(c) 5 x 6 tracks = 40 l x 48 l = 1920 l2. (with a bit of care)
(d-e) The layout should be similar to the stick diagram.
1.16
(c) 6 tracks wide x 7 tracks high = (48 x 56) = 2688 l2.
(a) (b)
A
B
C
Y
A
VDD
GND
B C
Y
(d)
(b)
A B
C
A
VDD
GND
B C
F
D
A
B C
D
(a)
D
F
A B
C
C
A B
B
A
A
B
(a)
Y
B
VDD
GND
A C
Y
A B
(b)
CHAPTER 2 SOLUTIONS 7
1.17 20 transistors, vs. 10 in 1.16(a).
1.18
(c) The area of this stick diagram is 11 x 6 tracks = 4224 l2 if the polysilicon can be
bent.
1.19 The lab solutions are available to instructors on the web.
Chapter 2
A
Y
B
A
C
B
C
G0
G1
G2
G3
P1
P2
P3
G3
G2 P3
G1 P2
G0 P1
G
(a)
VDD
GND
G0 P1 G1 P2 G2 P3 G3
(b)
G
8 SOLUTIONS
2.1
2.2 In (a), the transistor sees Vgs = VDD and Vds = VDS. The current is
In (b), the bottom transistor sees Vgs = VDD and Vds = V1. The top transistor sees Vgs
= VDD - V1 and Vds = VDS - V1. The currents are
Solving for V1, we find
Substituting V1 indo the IDS2 equation and simplifying gives IDS1 = IDS2.
2.3 The body effect does not change (a) because Vsb = 0. The body effect raises the
threshold of the top transistor in (b) because Vsb > 0. This lowers the current
through the series transistors, so IDS1 > IDS2.
2.4 Cpermicron = eL/tox = 3.9 * 8.85e-14 F/cm * 90e-7 cm / 16e-4 mm= 1.94 fF/mm.