ICS 51: Introduction to Computer Organization Sample problems #9 on Spring 2020
1. Suppose that one of the following control signals in the single-cycle MIPS processor has a stuck-at-0 fault, meaning that the signal is always 0, regardless of its intended value. What instructions would malfunction? Why?
(a) RegWrite (b) ALUOp1
(c) MemWrite
Answer:
2. Modify the single-cycle MIPS processor to implement slti instrution. Necessary changes you may want to make or not: 1. ALU and ALU decoder, 2. Datapath in MIPS architecture below, and 3. Main decoder truth table below:
3. Repeat the previous question for sll instruction. (This question helps you to understand how to implement shift instructions in MIPS architecture.)
Hint: sll is a r-type instruction and you should make changes in ALU. (You probably want to use shamt bit field in instruction to implement this instruction.)