使用LC-3模拟器完成Assignment

COMPSCI 210 S2 – Assignment 01
Computer Science
COMPSCI 210 S1
Assignment ONE

This assignment is to be done using LC-3 simulator. You can download the JAVA version from Canvas. You can use the simulator to compile and test the program.
Section 1: Running the Simulator [1] (1 mark)
You can execute the simulator (‘LC3sim.jar’). We need to first load some software. The first piece of software we should load is, naturally, an operating system. The LC-3 operating system is very basic: it handles simple I/O operations and is responsible for starting other programs. Download the LC-3 OS (‘LC3os.asm’) and you can understand what the operating system does.
The LC-3 machine doesn’t understand assembly directly; we first have to ‘assemble’ the assembly code into machine language (it is an ‘.obj’ file containing binary data). The LC-3 simulator has a built-in assembler, accessible (as is the case for most of its functionality) via the Command Line text box. To assemble the operating system, type as lc3os.asm at the command line and hit enter. Make sure that the OS file is in the same directory as the ‘.jar’ file; the as command also understands relative and absolute paths if the OS is in a different directory. Output from the assembly process is displayed in the CommandLine Output Pane. After assembling the OS, you should notice that 2 new files, ‘lc3os.obj’ and ‘lc3os.sym’, have been created. The ‘.obj’ file is the machine language encoding of the assembly language file, and the ‘.sym’ file is a text file that holds symbol information so the simulator can display your symbols. Recall that symbols are really just a convenience for silly humans; the machine language encoding knows only about offsets.
Now we can load the ‘lc3os.obj’ file into the simulator, either via the command load lc3os.obj or by going to the File menu and selecting Open ‘.obj’ file. Notice that the contents of the memory change when the OS is loaded. Now assemble and load the solution file for Problem 0 (Q0.asm) into the simulator. The memory has changed again, but you may not notice since the relevant memory addresses (starting at x3000) aren’t visible unless you’ve scrolled the screen. User-level programs (i.e., non-OS code) start, by convention, at x3000. If you type the command list x3000 the memory view will jump to x3000 and you can see the 1-instruction solution to this problem.
To actually run code, you can use the 4 control buttons at the top of the simulator, or type commands into the command line interface (the command names are the same as the buttons). Note that the PC register is set to x0200, which is the entry point to the operating system by convention. You can set the value in the registers. Example: You can set the value of R2, either by double-clicking it in the Registers section, or via the command set R2 (value). Now, actually run the code by hitting the continue button. You can find more details of operations from [1].
In section 1, you are going to revise the program below. This program will take two input operands and output the AND results of those inputs. You first assemble all the files: ‘lc3os.asm’, ‘data.asm’ and ‘Q0.asm’. Hence, you execute the following commands: load lc3os.obj, load data.obj and load Q0.obj. Click ‘continue’ to run the program. You can see the results from the display at the bottom-left.
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COMPSCI 210 S2 – Assignment 01
;
; Initialization ;
;
REDO LDR ;
; Test character for end ;
x3000
R6, EMPTY R5, PTR R0, R0, #0 R0, R0, #10
R3, R5, #0 of file
.ORIG LD LD AND ADD OUT
; R6 is the stack pointer
; R5 is pointer to characters
; Print a new line
; R3 gets character
; Test for end of line (ASCII xA) ; If done, quit
; Get the decimal value from ASCII
; check odd/even
; Save the first operand to R2
; ‘+’, revise the sign here for the corresponding operation
; ‘=’
; Print a new line
ADD BRz LD ADD JSR ADD AND BRz ADD LD OUT BRnzp
EVEN LD OUT
;
JSR AND ADD OUT BRnzp
;
; A subroutine to output a 3-digit decimal result. ;
CONV ………. …………………………..
EXIT HALT
R4, R3, #-10 EXIT
R4, ZERO R3, R3, R4 CONV
R5, R5, #1 R4, R5, #1 EVEN
R2, R3, #0 R0, PLUS
REDO
R0, EQUAL
CONV
R0, R0, #0 R0, R0, #10
REDO
; Start calculation ; You only need to revise this section for the operations
AND R3, R2, R3 ; The second operand is at R3
; Halt machine
You now revise the program of the sample file (Q0.asm) so the output will display the addition result (sum) of every two input values from the “data.asm”. Save the program as the file Q1.asm.
009+008=017
008+007=015
007+006=013 006+005=011 005+004=009 004+003=007 003+002=005 002+001=003
WARNING: We will use the JAVA simulator for marking. In particular, you should make sure that your answer will produce ONLY the exact output expected. The markers simply makes an exact comparison with the expected output. If you have any debug printouts or other code which produces some unexpected output, the markers will give you zero marks. If your files cannot be compiled successfully or they cannot be executed after compilation, the markers will also give you zero marks.
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Section 2: Hexadecimal Representation (2 marks)
You now revise the program of the section 1 (Q1.asm) so the output will display the correction equation and the addition result of every two input values from the “data.asm” in hexadecimal representation. Save the program as the file Q2.asm.
For example (data from ‘data.asm’): 009+008=011
008+007=00F
007+006=00D
006+005=00B 005+004=009 004+003=007 003+002=005 002+001=003
You need to revise the CONV subroutine to display the result in hexadecimal representation. You can revise it based on the following template (you can check Lecture 17 for more information).
COMPSCI 210 S2 – Assignment 01
CONV ADD R1, R7, #0 JSR Push
ADD R1, R3, #0 JSR Push ADD R1, R4, #0 JSR Push ADD R1, R5, #0 JSR Push AND R5, R5, #0
;
;
; Your code is here ;
;
;
JSR Pop
ADD R5, R1, #0 JSR Pop
ADD R4, R1, #0 JSR Pop
ADD R3, R1, #0 JSR Pop
ADD R7, R1, #0 RET
; R3, R4, R5 and R7 are used in this subroutine ; R3 is the input value
PRINT ADD
JSR Push
ADD R0, R0, #-10 BRn PINT
LD R1, CHAR_A ADD R0, R1, R0 OUT
JSR Pop
ADD R7, R1, #0 RET
; R3, R4, R5 and R7 are used in this subroutine
PINT ADD
LD R1,
ADD R0, OUT
JSR Pop ADD R7, RET
R0, R1 R1, #0
R1, R7, #0
R0, R0, #10 ASCII
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Section 3: Subtraction (1 mark)
You now revise the program of the section 2 (Q2.asm) so the output will display the correction equation and the subtraction result of every two input values from the “data.asm” (you can check Lecture 3 for more information). Save the program as the file Q3.asm.
For example (data from ‘data.asm’): 009-008=001
008-007=001
007-006=001
006-005=001 005-004=001 004-003=001 003-002=001 002-001=001
Section 4: Multiplication (2 marks)
You now revise the program of the section 2 (Q2.asm) so the output will display the correction equation and the multiplication result of every two input values from the “data.asm” (you can check Lecture 13 for more information). Save the program as the file Q4.asm.
For example (data from ‘data.asm’): 009*008=048
008*007=038
007*006=02A
006*005=01E 005*004=014 004*003=00C 003*002=006 002*001=002
Section 5: Factorial (2 marks)
You now revise the program of the section 2 (Q2.asm) so the output will display the correction equation and the factorial result of every input value from the “data1.asm” (you can check Lecture 15 for more information). Save the program as the file Q5.asm.
For example (data from ‘data1.asm’): 006!=2D0
005!=078
004!=018
003!=006 002!=002 001!=001
Remarks:
1. All input value should be between 00010 – 00910.
2. The results of all output should be between 00016 – FFF16.
3. All inputs and outputs should be positive.
4. There should not be any invalid inputs from the input data file.
COMPSCI 210 S2 – Assignment 01
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COMPSCI 210 S2 – Assignment 01
Submission
You may electronically submit your assignment through the Web Dropbox (https://adb.auckland.ac.nz/) at any time from the first submission date up until the final date. You can make more than one submission. However, every submission that you make replaces your previous submission. Submit ALL your files in every submission. Only your very latest submission will be marked. Please double check that you have included all the files required to run your program.
No marks will be awarded if your program does not compile and run. You are to electronically submit all the following files:
1. Q1.asm for section 1
2. Q2.asm for section 2
3. Q3.asm for section 3
4. Q4.asm for section 4
5. Q5.asm for section 5
There will be 30% penalty on late submission. The period of late submission will be 2 weeks after the deadline. No more submission will be allowed after that period.
Integrity
Any work you submit must be your work and your work alone. To share assignment solutions and source code is not permitted under our academic integrity policy. Violation of this will result in your assignment submission attracting no marks, and you will face disciplinary actions in addition.
Reference
[1] http://www.cis.upenn.edu/~milom/cse240-Fall05/handouts/lc3guide.html
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