CS 1541 Computer Architecture Homework 3 - Spring 2003, Assignments of Computer Science

Download CS 1541 Computer Architecture Homework 3 - Spring 2003 and more Assignments Computer Science in PDF only on Docsity! 1 of 2 CS 1541 Computer Architecture - Spring 2003 Homework #3 Assigned: Wednesday, January 29. Due: Wednesday, February 5. All homeworks are due at the beginning of class. Assignment (1) Consider executing the code given below on the pipelined datapath of Figure 6.46 on page 492 in the book: add $1, $2, $3 add $4, $1, $5 lw $7, 0($8) add $10, $7, $9 sw $10, 0($8) (a) At the end of sixth cycle of execution, which registers are being read and which are being writ- ten ? (b) With regard to the above question, explain what the forwarding unit is doing during the sixth cycle of execution. Mention the comparisons being made, if any. (c) With regard to the program in (1), explain what the hazard detection unit is doing during the fifth cycle of execution. Mention the comparisons being made, if any. (2) Consider executing the code given below on the pipelined datapath of Figure 6.46 in book on page 492. addi $5, $1, 200 lw $4, 100($5) add $6, $4, $4 sw $6, 100($5) xor $6, $3, $6 How many cycles will it take to execute this code? Draw a diagram like that on page 489 in book and illustrate the dependencies that need to be resolved and draw another diagram like that on page 491 (Figure 6.45) to illustrate how the code will actually be executed (incorporating any stalls or forwarding) so as to resolve the identified problems.