1. What is the formula to determine the execution time of a program. For each of the three terms in this formula, tell whether RISC or CISC processors do a better job of minimizing the term.
  2. If a program spends 25% of its running time doing integer division, how much speedup would be achieved by adding hardware that makes integer division run twice as fast?
  3. How many bits are needed to provide addresses for a 128 KB memory?
  4. Describe the format of the MIPS slt instruction. Tell the number of bits for each field, and what the instruction does.
  5. Show the format of the MIPS bne instruction. Tell the number of bits for each field, what the instruction does, and how the branch target address is computed.
  6. Show the format of the MIPS jmp instruction. Tell the number of bits for each field, what the instruction does, and how the branch target address is computed.
  7. Draw the gates to implement a multiplexor with two control inputs. Label all inputs and outputs.
  8. Draw a diagram showing the internal structure of cell number 31 for the ALU designed in the textbook for a MIPS processor.
  9. Tell the reason for implementing carry-lookahead logic. Give the equations for carry generate and carry propagate and for C1 through C3.
  10. Complete the given rows of the following truth table for the four-bit parallel adder-subtracter designed in class. Answer on this sheet. Notes: a/s is the add/subtract control (0 means add), c is the carry out of the left-most bit, v is the arithmetic overflow indicator, n is the negative result indicator, and z is the zero result indicator. You do not have to show the values for B' as we did in class.
A3 A2 A1 A0 B3 B2 B1 B0 a/s      C   V   N   Z   S3   S2   S1   S0         

0  1  1  1  1  0  0  1   0                                                 

0  0  1  0  0  1  1  0   1                                                 

0  1  1  1  0  1  0  0   0                                                 



Christopher Vickery
Computer Science Department
Queens College of CUNY