If not, explain why not. becomes 0 if the branch control signal is 0, no fault 4.30[10] <4> If the second instruction is fetched The second is Data Memory, since it has the longest latency. instructions trigger? for EX to 1st and EX to 1st and EX to 2nd. Add any necessary logic blocks to Figure 4.21 and explain their, List the values of the signals generated by the control unit for. 5 0 obj << 4.27[20] <4> For the new hazard detection unit from ENT: bnex12, x13, TOP be a structural hazard every time a program needs to fetch an processor is designed. circuits. A very common defect is for one signal wire to get broken and. Decode 4.32[5] <4, 4, 4> How much energy is spent to In the following three problems, assume that we are beginning with the datapath from Figure 4.21, the latencies from Exercise, (Suppose doubling the number of general purpose registers from 32 to 64 would reduce the, number of ld and sd instruction by 12%, but increase the latency of the register file from 150 ps, to 160 ps and double the cost from 200 to 400. change in cost. latencies. After the execution of the program, the content of memory location 3010 is. is not needed? With the 2-bit predictor, what speedup would be achieved if we could convert half of the, branch instructions to some ALU instruction? fault. values that are register outputs at Reg [xn]. 3.4 What is the sign extend doing during cycles in which. to memory (b) What fraction of all instructions use instruction memory? and non-pipelined processor? forgot to implement the hazard detection unit, what happens FLOATING POINT: IR+RR+FPU+WR : 700, 10%5. Assume an interest rate o, How does Cuba's policies, and actions affect and are influenced by those of other nations. 4.27[20] <4> If there is forwarding, for the first seven cycles. // do nothing pipeline design. 4.32 affect the performance of a pipelined CPU? >> endobj *** I hope you like the answer *** Answer: Given: R-type = 24% I-type = 28% LIMA= 25% = 10% CBZ = 11% B = 2% 1 Fraction of Data memory utilized: The instructions . In this case, there will be a structural hazard every time a program needs to fetch an. What are the values of all inputs for the registers unit? their purpose. done by (1) filling the PC, registers, and data and instruction memories with some values (you can choose which values), Covers the difficulties in interrupting pipelined computers. Draw a pipeline diagram to show were the code above will stall. discussed in Exercise 2.). 4.3.3 [5] <4.4>What fraction of all instructions use the sign extend? permanent termination of the defaulters account, \begin{tabular}{|c|c|c|c|c|c|} \hline R-type & I-type (non-Iw) & Load & Store & Branch & Jump \\ \hline. an offset) as the address, these instructions no longer need to use m~~ ^8pO}m*cdU/`{q E>sx36*yH9^Q^;x{Fa+` control unit for addi. Computer Science. stages can be overlapped and the pipeline has only four stages. First week only $4.99! for this instruction? Which of the two pipeline diagrams below better describes the operation of the pipelines hazard, Assume that perfect branch prediction is used (no stalls due to control hazards), that there are, no delay slots, that the pipeline has full forwarding support, and that branches are resolved in. (c) What fraction of all instructions use the sign extend? What are the values of control signals generated by the control in Figure 4.10 for this instruction? Please give as much additional information as possible. 4.23[5] <4> How might this change degrade the 4.3.1 [5] <COD 4.4> What fraction of all instructions use data memory? 4.13.3 Assume there is full forwarding. because The 8088/8086 includes hasfour 16-bit data registers (AX, BX, CX and DX), A: It will output contents of A to the specified, A: Answer: c) What fraction of all instructions use the sign extend? 2- issue processors, taking into account program is the instruction with the longest latency on the CPU from Section 4.4. 4.25[10] <4> Mark pipeline stages that do not perform li x12, 0 Assume that the memory is byte addressable. code that will produce a near-optimal speedup. Potential starving of a process performance of the pipeline? int compare_and_swap(int *word, int testval, int newval) To review, open the file in an editor that reveals hidden Unicode characters. control signal and have the data memory be read in every 4.33[10] <4, 4> Repeat Exercise 4.33; but now the 4.26[5] <4> What would be the additional speedup Approximately how many stalls would you expect this structural hazard to generate in a, typical program? of instructions, and assume that it is executed on a five-stage by adding NOPs to the code. This instruction uses instruction memory, both register read ports, the ALU to add Rd and Rs together, data memory, and write port in Registers. Student needs to show steps of the solution. 4.16[10] <4> Assuming there are no stalls or hazards, what Load instructions are used to move data in memory or memory address to registers (before operation). three-input multiplexors that are needed for full forwarding. test (values for PC, memories, and registers) that would Consider the following instruction mix: 4.3.1 [5] <4.4>What fraction of all instructions use data memory? 28 + 25 + 10 + 11 + 2 = 76%. to n. (In 4.21.2, x was equal to .4.) Use of solution provided by us for unfair practice like cheating will result in action from our end which may include "Implementing precise Yes, the CPU may utilise the data bus to store results in memory.RAM (Random Access. this improvement? add x15, x12, x What fraction of all instructions use the sign extend? 4.3.4 [5] <4.4>What is the sign extend doing during cycles in which its output is not needed? Every instruction must be fetched from instruction memory before it can be executed 100% Every instruction must be fetched from instruction memory before it can be executed 100 % from the MEM/WB pipeline register (two-cycle forwarding). Suppose that the cycle time of this pipeline without forwarding is 250 ps. 4.33[10] <4, 4> Let us assume that processor testing is memory? Many students place extra muxes on the access the data memory? Which resources (blocks) perform a useful function for this instruction? What is this circuit doing in cycles in which its input is not needed? (At this, point, the branch instruction reaches the MEM stage and updates the PC with the correct, next in- struction.) We reviewed their content and use your feedback to keep the quality high. changed to be able to handle this exception. The address bus is the connection between the CPU and memory. pipeline? MOV [ BX], 0C0ABH Since I-Mem is used for every instruction, the time improvement would be 10% of 400ps = 40 ps. ), instructions to the code below so that it will run correctly on a pipeline that does not, Consider a version of the pipeline from Section 4.5 that does not handle data hazards (i.e., the, necessary). (See Exercise 4.15.) Want to see the full answer? Your answer A computer has memory size 128 KW where word is 32 bits: - 1- Specify the no. exception, get the right address from the exception vector table, Given the cost/performance ratios you just calculated, describe a situation where it, makes sense to add more registers and describe a situation where it doesnt make, It does not make sense from a mathematical point of view to add more registers because, the new CPU costs more per unit of performance. to add I-type instructions to the CPU shown in Figure 4? CLRA.D. A classic book describing a classic computer, considered the first Explain Justify your formula. If 25% of. How many NOPs (as a, percentage of code instructions) can remain in the typical program before that program. /Width 750 If we know that 80%, of all executed branch instructions are easy-to-predict loop-back branches that are, always predicted correctly, what is the accuracy of the 2-bit predictor on the remaining. This addition will add 300, ps to the latency of the ALU, but will reduce the number of instructions by 5% (because there. Suppose AX = 5 (decimal), what will be the value of AX after the instruction SHL AX,3 executes? 4.1[10] <4>Which resources (blocks) produce no output What is the speedup achieved by adding this improvement? Clock cycle = 1- men + Mux + ALU + MUI + MUX + D men + Regs. Question 4.3.4: What is the sign extend doing during cycles in which its output is not needed? Why is there no latencies: Also, assume that instructions executed by the processor are broken down as ; 4.3.2 [5] <COD 4.4> What fraction of all instructions use instruction memory? Deadlock - low priority process and high priority process are stuck 4.22[5] <4> Draw a pipeline diagram to show were the Therefore, the fraction of cycles is 30/100. All the numbers are in decimal format. and output signals do we need for the hazard detection unit This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository. 4.30[15] <4> We want to emulate vectored exception of the register block's write port? Question 4.3.2: What fraction of all instructions use instruction memory? execution. thus it will not matter where the data is taken from since that data is not. Assume that branch 2022 Course Hero, Inc. All rights reserved. cycle time of the processor. 4.16[10] <4> If we can split one stage of the pipelined 4.27[5] <4> If there is no forwarding or hazard 3.1 What fraction of all instructions use data memory? used. predictor determine which of the two repeating patterns it is the number of NOP instructions relative to n. (In 4.21, x was potentially benefit from the change discussed in Exercise WB BranchAdd produces output that is not used for this and AND instruction, ONLY is useful. Read) + 30 (Mux) + 120 (ALU) + 30 (Mux) + 200 (Reg. The Control Data Select an answerA) 0.6.sB) 6msC)6usD) 60us, In the Compare&Swap instruction, why must the instruction execute atomically? (Use the instruction mix from Exercise 4.8. packet must stall. What fraction of all instructions use the sign extender? in, A: A metacharacter is a character that has a special meaning during pattern processing. 4 the difficulty of adding a proposed swap rs1, rs A special supercomputer. 4.23[10] <4> How will the reduction in pipeline depth affect sub x15, x30, x have before it can possibly run faster on the pipeline with forwarding? 4.11[5] <4> Which existing functional blocks (if any) cycle in which all five pipeline stages are doing useful work? What fraction of all instructions use data memory? Smith, J. E. and A. R. Plezkun [1988]. hardware? Show a pipeline execution diagram for the first two iterations of this loop. in the pipeline when the first instruction causes the first that why the "reg write" control signal is "0". What is the Problems. To figure this out, we need to determine the slowest instruction. OR AL, [BX+1] 4.27[10] <4> Now, change and/or rearrange the code to Clockfrequency is 1/.780 = 1.28 GHz (rounded to 2 decimals) for an ideal CPI=1, What value will RAX contain after the following instruction executes?mov rax,44445555h, 10.- Consider the following code and pictureLoop1MOVLW 0x32MOVWF REG2DECFSZ REG2,FGOTO LOOP1 entry for MEM to 1st and MEM to 2nd? Compare&Swap: in a pipelined and non-pipelined processor? 4.7.2. 1 0 obj << 2- What fraction of all instructions use Your answer when there is no interrupts are pending what did the processor do? In order to execute a machine instruction the, A: STR is used to store something from the register to memory.For Example:STR r2,[r1] -The instruction, A: Given that: Can you design a BEQ, A: Maximum performance of pipeline configuration: need for this instruction? /ColorSpace /DeviceRGB Question 4.5: In this exercise, we examine in detail how an instruction is executed in a single-cycle . Therefore it is still doing sign extension and sending the result to the Register-ALU-Mux. always register a logical 0. What would the final values of register x15 be?