HWK14 - 14.1 a) Interrupt vector table at address x0188...

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14.1 a) Interrupt vector table at address x0188 contains start of interrupt routine, x6600 x0188 x6600 ;interrupt vector table b) STR R0, R6, #-1 ;push R0 STR R1, R6, #-2 ;push R1 STR R2, R6, #-3 ;push R2 STR R3, R6, #-4 ;push R3 STR R4, R6, #-5; ;push R4 STR R5, R6, #-6 ;push R5 STR R6, R6, #-7 ;push R6 STR R7, R6, #-8 ;push R7 ADD R6, R6, #-8 ;Move stack pointer c) Include previous assembly segment from above at address x6600, And then one of the following code segments Solution A (Assume x3000 address is below code for service routine in memory) BRnzp #1 X3000 STI R0, #-2 ; Save R0 to x3000 LD R0, #-3 ; Load x3000 to R0 STR R1, R0, #1 ; Save R1 to x3001 STR R2, R0, #2 ; Save R2 to x3002 STR R3, R0, #3 ; Save R3 to x3003 STR R4, R0, #4 ; Save R4 STR R5, R0, #5 ; Save R5 STR R6, R0, #6 ; Save R6 STR R7, R0, #7 ; Save R7 Solution B (Create x3000 address) ADD R6, #-1 ADD R6, #-1 STR R5, R6, #0 AND R4, R4, #0 ; Clear R4 ADD R5, R4, #-8 ; load 11000 ADD R4, R4, #10 ; set loop counter ADD R5, R5, R5 ; SHL (beginning of loop) ADD R4, R4, #-1 ; decrement counter BRp #-3 ; shift left 10 times STR R0, R5, #0 ; Save R0 at x3000 STR R1, R5, #1 ; Save R1 at x3001 STR R2, R5, #2 ; Save R2 STR R3, R5, #3 ; Save R3 ADD R6, #1 ; from stack
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LDR R1, R6, #0 ADD R6, #1 STR R1, R5, #4 ; Save old R4 value STR R0, R5, #5 ; Save old R5 value STR R6, R5, #6 ; Save R6 STR R7, R5, #7 ; Save R7 14.2 a) b) 14.3 a) One ethical issue with the “hacker ethic” involves the principle that all information is free. i) Guidelines included the in the ACM Code of Ethics are directly relevant to this issue: 1.5 Honor property rights including copyrights and patents, 1.7 Respect the privacy of others, 1.8 Honor confidentiality. We can also use the common practice test and reversibility tests to evaluate this issue, 2.8 Access computing and communication resources only when authorized to do so. ii) Obviously, if all information was free, then privacy, confidentiality, and intellectual property would all be impossible. We therefore find that the above ACM codes are violated. Privacy is an important individual right which would be violated by people who follow the hacker principles and disseminate private information. Furthermore, some information may be deemed confidential by companies or other organization, so the hacker may in fact be breaking secrecy laws by revealing information. (Legality test). Although details of IP laws can be further debated, it is clear that some information should be protected by law, in order to encourage scientific progress and technological innovation. iii)
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This note was uploaded on 02/26/2010 for the course ECE 290 taught by Professor Brown during the Fall '08 term at University of Illinois at Urbana–Champaign.

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HWK14 - 14.1 a) Interrupt vector table at address x0188...

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