Homework 3 - Chapter 5

1. (4pts) For the following instructions parsed by the simple datapath, state whether or not they would be affected by a stuck-at-1 error for bit 0 of ALUOp. If it is affected, state what would go wrong.
   1. load word (lw)
   2. store word (sw)
   3. branch equal (beq)
   4. R-type instructions
2. (4pts) For the following instructions parsed by the simple datapath, state whether or not they would be affected by a stuck-at-0 error for RegWrite. If it is affected, state what would go wrong.
   1. load word (lw)
   2. store word (sw)
   3. branch equal (beq)
   4. R-type instructions
3. (2pts) Give all the steps needed on the simple datapath to parse the instruction sub $t0, $s5, $t1.
4. (2pts) What control lines and functional units would be needed to expand the simple datapath to support the jump register (jr) instruction?
5. (2pts) What are the motivations behind the changes made to convert the simple datapath into the multicycle datapath? Describe how the changes address some deficiency in the simple datapath.
6. (2pts) Give all the steps needed on the multicycle datapath, including the control lines set at that step, to parse the instruction sub $t0, $s5, $t1.
7. (4pts) For the following instructions parsed by the multicycle datapath, state whether or not they would be affected by a stuck-at-0 error for ALUSrcA. If it is affected, state what would go wrong.
   1. load word (lw)
   2. store word (sw)
   3. branch equal (beq)
   4. R-type instructions