Sample Exam 2
1. Suppose the following hex value for a 2-byte integer is to be stored in memory. Show how the
number would be stored on a big-endian machine and a little-endian machine:
Value: 492C
machine type
high byte
low byte
big-endian
little-endian
2. Use the binary Pep-8 program shown in the second column of the table below to fill in the rest
of the table. The beginning address of the program is given:
Address
Instruction/Data
(Hex)
0000
Hex
value
Explanation (if instruction, indicate what it does; if data, give
decimal value)
1100 0001 0000 0000 0000
1110
1010 0001 0000 0000 0001
0000
1111 0001 0000 0000 0000
1101
0101 0001 0000 0000 0000
1101
0000 0000
0000 0000
0000 0000 0011 0000
0000 0000 0000 1111
3. What occurs during the decoding phase of the fetch/execute cycle?
4. How does memory distinguish between data and instructions?
5. Is the Pep/8 a big endian or little endian machine? Justify your answer.
6. Why does the number of clock cycles needed to execute an 80x86 instruction vary? What are
the best-case and worst-case scenarios for the amount of clock cycles required?
7. How did the VAX architecture contribute to the development of high-level languages?
8. Describe a JVM stack frame – you may use a labeled drawing to illustrate your narrative.