4.7 Problems in this exercise assume that the logic blocks used to implementa processor's datapath have the following latencies: Single Register Register Sign -Mem/Register D-MemFile Mux ALU Adder gate Read S Setup extend Control "Register read" is the time needed after the rising clock edge for the new register value to appear on the output. This value applies to the PC only. "Register setup" is the amount of time a register's data input must be stable before the rising edge of the clock. This value applies to both the PC and Register File. 4.7.1 [20] Although the control unit as a whole requires 50ps, it so happens that we can extract the correct value of the Reg2Loc control wire directly from the instruction. Thus, the value of this control wire is available at the same time as the instruction. Explain how we can extract this value directly from the instruction. Hints: Carefully examine the opcodes shown in Figure 2.20. Also, remember that LSR and LSL do not use the Rm field. Finally, ignore STXR. 4.7.2 [5] What is the latency of an R-type instruction (i.e., how long must the clock period be to ensure that this instruction works correctly)? 4.7.3 (10 $4.4> What is the latency of LDUR? (Check your answer carefully Many students place extra muxes on the critical path.) 4.7.4 [10 What is the latency of STUR? (Check your answer carefully Many students place extra muxes on the critical path.) 4.7.5 [5] What is the latency of CBZ? 4.7.6 15] What is the latency of B? 4.7.7 (5] What is the latency of an I-type instruction? 4.7 Problems in this exercise assume that the logic blocks used to implementa processor's datapath have the following latencies: Single Register Register Sign -Mem/Register D-MemFile Mux ALU Adder gate Read S Setup extend Control "Register read" is the time needed after the rising clock edge for the new register value to appear on the output. This value applies to the PC only. "Register setup" is the amount of time a register's data input must be stable before the rising edge of the clock. This value applies to both the PC and Register File. 4.7.1 [20] Although the control unit as a whole requires 50ps, it so happens that we can extract the correct value of the Reg2Loc control wire directly from the instruction. Thus, the value of this control wire is available at the same time as the instruction. Explain how we can extract this value directly from the instruction. Hints: Carefully examine the opcodes shown in Figure 2.20. Also, remember that LSR and LSL do not use the Rm field. Finally, ignore STXR. 4.7.2 [5] What is the latency of an R-type instruction (i.e., how long must the clock period be to ensure that this instruction works correctly)? 4.7.3 (10 $4.4> What is the latency of LDUR? (Check your answer carefully Many students place extra muxes on the critical path.) 4.7.4 [10 What is the latency of STUR? (Check your answer carefully Many students place extra muxes on the critical path.) 4.7.5 [5] What is the latency of CBZ? 4.7.6 15] What is the latency of B? 4.7.7 (5] What is the latency of an I-type instruction