Homeworks
Homeworks κ΄λ ¨
hw01
2.1
Give the entire count sequence of binary patterns for 3-bit unsigned integers.
2.2
What is the decimal value represented by the 8-bit binary number when interpreted as:
(a) an unsigned number?
(b) A 2's-complement number?
2.3
What is the decimal value represented by the binary number when interpreted as:
(a) an sign + magnitude number?
(b) A 2's-complement number?
2.4
Use polynomial evaluation to:
(a) Convert $$101101_2$$ to base 10
(b) Convert $$\text{DEAF}_{16}$$ to base 10.
(c) Convert $$0.324_7$$ to base 10.
2.5
Use repeated division to:
(a) Convert $$150_{10}$$ to base 2.
(b) Convert $$1500_{10}$$ to base 16.
(c) Convert $$400_{10}$$ to base 7.
2.6
Use repeated multiplication to:
(a) Convert $$0.9_{10}$$ to base 2.
(b) Convert $$0.9_{10}$$ to base 16.
(c) Convert $$0.9_{10}$$ to base 3.
2.7
Use shortcuts based on power relationships to:
(a) Convert to base 2.
(b) Convert to base 8.
(c) Convert to base 8.
(d) Convert to base 8.
(e) Convert $$17.6_9$$ to base 3.
2.8
Perform the indicated conversions:
(a) Convert $$\text{FA}.\text{CE}_{16}$$ to base 2 (binary).
(b) Convert $$101011.01101_2$$ to base 16 (hexadecimal).
(c) Convert $$56.23_{10}$$ to base 2 (binary).
(d) Convert $$11011.01101_2$$ to base 10 (decimal).
(e) Convert $$12.34_5$$ to base 7.
2.9
Convert the decimal number $$-37.1_{10}$$ to 16-bit 2's-complement binary, with 8 bits of integer part and 8 bits of fractional part.
2.10
What is the 2's-complement 8-bit representation of $$-100_{10}$$?
2.11
Give the 2's-complement 8-bit representation of $$-7.7_{10}$$, with the binary point in the middle (e.g. $$bbbb.bbbb$$).
2.12
For each of the following 2's-complement numbers, give the corresponding 8-bit representation of the negative of its value:
(a) $$01010101.$$
(b) $$10101010.$$
(c) $$1000.0001$$
(d) $$0111.1110$$
2.13
Consider a 2's complement number represented by $$n$$ bits, with the binary point placed between the two most significant bits (e.g., $$b.bb\cdots{b}$$).
(a) Give an algebraic expression in terms of $$n$$ for the positive value that has the smallest nonzero magnitude.
(b) Give the binary representation of (a). where $$n$$ is 8.
(c) Give an algebraic expression in terms of $$n$$ for the negative value that has the smallest nonzero magnitude.
(d) Give the binary representation of (c). where $$n$$ is 8.
2.14
Give the 32-bit binary representation of the floating-point value $$-25.1$$:
2.15
The ASCII code for the symbol β0β is $$30_{16}$$. Use this fact to determine the hex constants that would be stored in memory, starting at $$N$$, for the $$C$$ character string β12345β:
2.16
Perform the indicated addition on the following 4-bit operands, filling in all the indicated fields:
2.17
Perform the indicated subtraction on the following 4-bit operands, filling in all the indicated fields:
2.18
If the operands are unsigned, then does an overflow occur:
(a) In problem 16?
(b) In problem 17?
2.19
If the operands are signed, then does an overflow occur:
(a) In problem 16?
(b) In problem 17?
2.20
Find the indicated sum of the following signed 8-bit 2's-complement numbers and the indicate which cause an arithmetic overflow to occur:
(a)
(b)
(c)
2.21
Find the indicated difference of the following signed 8-bit 2's-complement numbers and the indicate which cause an arithmetic overflow to occur:
(a)
(b)
(c)
2.22
Assume that the C assignment statement βs=a+b
β has just been executed, where all variables are declared as signed ints. Write a C expression that is true if and only if the addition results in an overflow.
2.23
Repeat problem 22 for the C assignment statement βs=a-b
β.
2.24
What is the most positive decimal value of a 6-bit 2's-complement number?
2.25
What is the most negative decimal value of a 6-bit 2's-complement number?
2.26
What is the minimum decimal value of a 6-bit unsigned number?
2.27
What is the maximum decimal value of a 6-bit unsigned number?
2.28
The exact binary representation of one-sixth ($$\tfrac{1}{6}$$) requires an infinite number of digits. Truncating it (discarding extra bits) to make it fit within a fixed-precision representation creates a representational error. What is the absolute error that results from storing one-sixth without rounding using $$8$$ fractional bits?
2.29
Overflow is impossible when subtracting one unsigned number from another. [T/F]
2.30
Overflow is impossible when subtracting two signed operands of the same sign. [T/F]
2.31
There are two representations of zero in 2's complement. [T/F]
2.32
If rollover occurs when incrementing an integer, there is an overflow. [T/F]
2.33
In 2's complement, the absolute values of full-scale negative and full-scale positive are identical. [T/F]