Solved Mixed Questions of Computer Architecture II: Hardware-Software | CS 366, Exams of Computer Architecture and Organization

Download Solved Mixed Questions of Computer Architecture II: Hardware-Software | CS 366 and more Exams Computer Architecture and Organization in PDF only on Docsity! CS 366 - Computer Architecture IE Midterm Exam #2 - Prof. Reed a Spring 2005 = What is your name?: (0 points} There are two sections: I. Short Questions ........4 AO points; (20 questions, 2 points each) IL Short Sections cf Code . . .60 points; (10 questions, 6 points each) 100 points total This test is worth 20% of your final grade. This test is open book and open notes. You havc 60 minutes. I. True/Faise: (2 pts. each) Stack frames in a recursive program must all be the same size. Addition using numbers of opposite signs never results in overflow. The stack in SPIM grows towards address 0. In a recursive program, every subprogram must store $ra on the stack. Mé-F vith a b eee Es A jump- table. in SPIM is used td implement the high -level donstruct ofa switch- case state- ment. Each entry in the jump table must be the same size. Everyphing ) yo aA PP Pe 7, For recursive programs to work properly in SPIM, parameter values must be stored and retrieved by the calling part of the program. Co i 244 ny faite 8 é . The same arithmetic circuit can be used to compare integers and IEEE 754 floating point numbers. . The PC is normally represented by 17 in Mythsim. . A carry-out at the most significant bit after an. addition of two signed numbers always indi- cates overflowB Ne 3 a fps fpr Ame . There are some values between 255 and 256 that cannot be represented using IEEE 764 sin- gle-precision floating point numbers. . The key to be abie to store very small values in IEEE 754 single-precision floating point for- mat in denormalized form is that there is no implicit 1. . Having a CDR (Control Data Register) speeds up the execution of a control program n-J] shifts are needed to implement multi- . For the binary multiplier circuit discussed i in clas plication of an 7 bit number. ae In Mythsim an instruction in memory can specify the operation: 12 <- 13 + r4 . The following two lines are equivalent: _ an e2_write, a_sel0, a_sell, alu_sel=0; r2_write, a_sel=3; CS 366 - Computer Architecture IL, Midterm Exam #2, page 1 of S 17, In class we saw how the 8-step instruction fetch in Mythsim could actually be implemented in only 5 steps with no additional resources needed. 4» aly : 18. We can write microcode in Mythsim to explicitly set a register to some valuc, without using memory at all. 19. In Mythsim the results of an operation can be written to multiple registers at once. 20. If for some reason we started running out of registers, we could use the MDR briefly as a temporary storage location. TH. Short Answer: (6 points each) 1. Consider the code given below. What does this code do? (Don’t give an explanation for cach line, but rather give the one-line summary that would be appropri- ate to use as the one line of documentation describing these two lines in a program.) ia: xor Stl, $t2, $t3 , bgez Sti, labei3 2. Briefly list and explain the two main kinds of hazards that can arise when using a pipelined implementa- tion of SPIM. CS 366 - Computer Architecture Ll, Midterm Exam #2, page 2 of 5