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计算机系统 I 作业 part1

Question

a)

\[E=\sum m(1,2,4,6)=\prod M(0,3,5,7)\]
\[F=\sum m(0,2,4,7)=\prod M(1,3,5,6)\]

b)

\[\bar E=\sum m(0,3,5,7)\]
\[\bar F=\sum m(1,3,5,6)\]

c)

\[E + F = \sum m(1,2,4,6) + \sum m(0,2,4,7) = \sum m(0,1,2,4,6,7)\]
\[E \cdot F = \sum m(1,2,4,6) \cdot \sum m(0,2,4,7) = \sum m(2,4)\]

d)

\[E=\sum m(1,2,4,6) = \bar X \bar Y Z + \bar X Y \bar Z + X \bar Y \bar Z + X Y \bar Z\]
\[F=\sum m(0,2,4,7) = \bar X \bar Y \bar Z + \bar X Y \bar Z + X \bar Y \bar Z + X Y Z\]

e)

\[E = \bar X \bar Y Z + Y \bar Z + X \bar Z\]
\[F = \bar X \bar Z + \bar Y \bar Z + X Y Z = (\bar X + \bar Y) \bar Z + X Y Z\]

也可以根据逻辑代数公式直接化简

Question

prime implicants : \(XZ, \bar X \bar Z, WX, W \bar Z\)

essential prime implicants : \(XZ, \bar X \bar Z\)

Question

\[\begin{aligned} AB\bar C + B\bar C\bar D + BC + \bar CD &= AB\bar C + B\bar C\bar D + BC + \bar CD + B\bar CD \\ &= AB\bar C + B\bar C + BC + \bar CD \\ &= AB\bar C + B + \bar CD \\ &= B + \bar CD \end{aligned}\]

Question

b)

prime implicants : \(XZ, \bar X \bar Z, \bar WX\bar Y, \bar W\bar Y\bar Z, WXY, WY\bar Z\)

essential prime implicants : \(XZ, \bar X \bar Z\)

\[F(W,X,Y,Z) = XZ + \bar X \bar Z + \bar WX\bar Y + WXY\]

Question

\(X = A\)

\[G_0 = G(0, B, C, D) = \bar BC + BD\]
\[G_1 = G(1, B, C, D) = \bar B \bar C + B\bar D\]

\(X = B\)

\[G_{00}=G_0(0, C, D) = C\]
\[G_{01}=G_0(1, C, D) = D\]
\[G_{10}=G_1(0, C, D) = \bar C\]
\[G_{11}=G_1(1, C, D) = \bar D\]

Question

\[F(A, B, C, D) = AB + B\bar C\bar D + \bar A\bar B D + ACD\]
\[F(0, 0, C, D) = D\]
\[F(0, 1, C, D) = \bar C\bar D\]
\[F(1, 0, C, D) = CD\]
\[F(1, 1, C, D) = 1\]

Question

  • 3.28

  • 3.29

Question

可以转化成判断 \(A+(2^4-1-B)+1\) 是否有进位,我们可以只需要 Adder 中的 Cout 来完成

\(A<B \to O = 0\) \(A\geq B \to O = 1\)

Question

  • 3.20 :

0x0C000000 = 0000 1100 0000 0000 0000 0000 0000 0000

two's complement interger = \(2^{26}\times 3\) = 201326592

unsigned interger = \(2^{26}\times 3\) = 201326592

  • 3.21 :

不会 MIPS

  • 3.22 :

0x0C000000 = 0000 1100 0000 0000 0000 0000 0000 0000

IEEE 754 single : 1 sign + 8 exponent + 23 fractions

\[\begin{matrix}\underbrace{0}\\\text{sign }\end{matrix}\begin{matrix}\underbrace{00011000}\\\text{exponent }\end{matrix} \begin{matrix}\underbrace{00000000000000000000000}\\\text{fractions}\end{matrix}\]

\((-1)^0 \times (1 + \text{0}) \times 2 ^ {\overline{00011000}\text{ - 127}} = 1 \times 2^{-103}\)

  • 3.23 :

single : 1 sign + 8 exponent + 23 fractions, bias = 127

\[63.25 = (111111.01)_2 = 1.1111101 \times 2^{101}\]

\(5 + 127 = (10000100)_2\)

\[\begin{matrix}\underbrace{0}\\\text{sign }\end{matrix}\begin{matrix}\underbrace{10000100}\\\text{exponent }\end{matrix} \begin{matrix}\underbrace{11111010000000000000000}\\\text{fractions}\end{matrix}\]
  • 3.24 :

double : 1 sign + 11 exponent + 52 fractions, bias = 1023

\(5 + 1023 = (10000000100)_2\)

\[\begin{matrix}\underbrace{0}\\\text{sign }\end{matrix}\begin{matrix}\underbrace{10000000100}\\\text{exponent }\end{matrix} \begin{matrix}\underbrace{1111101000000000000000000000000000000000000000000000}\\\text{fractions}\end{matrix}\]
  • 3.27 :

half precision : 1 sign + 5 exponent + 10 fractions, bias = 15

\(-1.5625\times 10^{-1} = -0.15625 = (-1) \times (0.00101) = (-1) \times (1.01) \times (2^{-11})\)

\(-3 + 15 = (01100)_2\)

\[\begin{matrix}\underbrace{1}\\\text{sign }\end{matrix}\begin{matrix}\underbrace{01100}\\\text{exponent }\end{matrix} \begin{matrix}\underbrace{0100000000}\\\text{fractions}\end{matrix}\]

32-bit has larger range and presion than 16-bit.

Question

D(t) X Y D(t+1) S
0 0 0 0 0
0 0 1 1 1
0 1 0 1 1
0 1 1 0 0
1 0 0 1 1
1 0 1 0 0
1 1 0 0 0
1 1 1 1 1
graph LR
    0[0] --> |00/0, 11/0| 0[0]
    0[0] --> |01/1, 10/1| 1[1]
    1[1] --> |00/1, 11/1| 1[1]
    1[1] --> |01/0, 10/0| 0[0]

Question

Question

a)

b) 待补充

Question

  • Ripple Counter

  • Synchronous Counter

待补充

Question

Question

a) \(t_a=2t_{XOR-pd}=0.08\text{ns}\)

b) \(t_b=t_{XOR-pd}+t_{Inv-pd}+T_s=0.07\text{ns}\)

c) \(t_c=t_{FlipFlop-pd}+2t_{XOR-pd}=0.16\text{ns}\)

d) \(t_d=t_{FlipFlop-pd}+t_{XOR-pd}+t_{Inv-pd}+T_s=0.15\text{ns}\)

e) \(\text{Clock frequency} = \frac{1}{t_d} = 6667 \text{MHz}\)