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JSPMs

Rajarshi Shahu College of EngineeringTathawde, Pune 33

Department of Information Technology

2011-12

Mid Term Test Marking SchemeClass: T.E Date: 06 /02/12

Subject: System Software Max Marks: 50

Time: 9.00 am to 10.30 am

Instructions:1) Draw neat diagrams wherever necessary.2) Assume suitable data if necessary.Q.1. Define the following terms 4

i. Compilerii. Loader

iii. Interpreteriv. Macro-processorAns: Definition and Explanation carries one mark for each term.

Q.2. Assume the instruction op-codes for assembly mnemonic as given below.Instruction op-code Mnemonic Length

00 STDP 1

01 ADD 1

02 SUB 1

03 MULT 1

04 MOVER 105 MOVEM 1

06 BC 1Generate Literal table, symbol table, intermediate code (using variant I) and target

code, for the assembly language code given below: 16START 200

MOVER AREG, = SMOVEM AREG, A

LOOP MOVER AREG, A

MOVER CREG, B

ADD CREG, = 1

BC ANY, NEXTLTORG

NEXT SUB AREG, = 1BC LT, BACK

LAST STOP

ORIGIN LOOP + 2

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MULT CREG, B

A DS 1

BACK EQU LOOPB DS 1

END

OR

Ans:

Literal Table showing literal and its address 4 M

symbol table Showing Symbol and its Address 4 M

Intermediate code in the format of Varient I 4 M

Q.1. Say true or false and justify your answer : 08i. Single pass assembler can handle forward references.

ii. Error, symbol used but not defined can be detected during pass I of two passassembler.

iii. Assembler directives get translated into object code.iv.

The literals used in assembly language get memory allocated only after END.Ans:

i. False, Justify 2 Mii. True, Justify 2 M

iii. False, Justify 2 Miv. False, Justify 2 M

Q.2. Draw the flowchart of activities of pass I of two pass assembler. 12Ans:

Activities of Pass I

Symbol Table Generation 3 MLiteral Table Generation 3 MProcessing of the IS, AD, DS 3 MIntermediate code Generation 3 M

Q.3. In an assembly language program certain action is required at ten different places.Under what conditions would you code this as i) Macro ii) Subroutine? Justify

your answer. 4

Ans:

Explain what is MACRO with an example 1 M

Explain Subroutine with an example 1 MDifferentiate between both by considering there processes ofdefinition and call.

2 MQ.4. Explain with example, different types of parameters that are used in macro

processor. 4

Ans:

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Enlist all Parameters

Explain Keyword Parameter 2 MExplain Positional Parameter 2 M

Q.5. Show macro name table, macro definition table and final expanded code for theassembly language code given below : 12MACRO

XYZ & AST 1, & A

MEND

MACROMPLS & Z

MACRO

&Z & W

AR 4, & WXYZ ALL

MENDST & Z, ALLMEND

PROG START

USING *, 15

MPLS HELLOST 2,3

HELLO YALE

YALE EQU 5ALL DC F3

END

name table, macro definition table and final expanded code for the

assembly language code

Ans:

Macro Name Table with Macro name and MNTC and MDTP 3 M

Macro Definition Table containing definition of all MACRO 3 MExpanded Source File which will have replaced all macro calls

with is definition having actual parameters.

3 M

OR

Q.3.

Explain the processing of all phases of compiler with respect to the assignmentstatement given below. Clearly mention input and output of each phase. p = i * r /30 where i is integer variable while p and r are float type variables. 12

Ans:

Give the detailed output of every phase and explain how it is

generated as there are six phases each phase will carry 2 marks

each.

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Q.4. Distinguish between top down and bottom up parsers. 4Ans:

Differentiate between Top Down and Bottom UP Parse 1 mark for

each point 4 points are expected.

Q.5. Explain with example the term ambiguous grammar. 4Ans:

Explain Ambiguous grammar with an example. 4 M

Question no. 06 is compulsory:Q.6. For the C code given below, give the different tables that would be generated as

output of lexical analysis.main ()

{

int i, sum, n;

float avg;

for (i = 1; i < = 10; i + +)

sum = sum + i ;

avg = sum / (float) n ;} 10

Ans:

Display the output as contents of each table.

.

Uniform Symbol Table 4 M

Literal Table 3M

Identifier Table 3M