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Answer:

0000 1111 1010 0101       0FA5
0011 0110 1000 1111       368F

0011 1001 0010 1010       392A

Example Program

Here is a program that does all three bitwise operations between the same two patterns. The destination register is different in each case.

## Program to bitwise OR, AND, and XOR two patterns 
        .text
        .globl  main

main:
        ori     $15, $0,0x0FA5       # put bit pattern register into $15
        ori      $8,$15,0x368F       # OR with second pattern
        andi     $9,$15,0x368F       # AND with second pattern
        xori    $10,$15,0x368F       # XOR with second pattern

## End of file

Running it in SPIM (pushing F10 four times) results in the following:

SPIM display of program results

The register display on the left shows the results of the three logic operations. Select "Hex" from the "Registers" menu to see register content displayed using hexadecimal pattern names. The registers always hold 32 bits (of course), but the register display does not show leading zeros. So the result of the xori operation given in the answer (see above) is displayed as

392a

corresponding to what is really in the register

0000392a   hexadecimal for   0000 0000 0000 0000 0011 1001 0010 1010

QUESTION 13:

What is the exclusive-OR of a bit pattern with itself? Try this with a few bit patterns written on a scrap of paper.


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