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Instruction formats:
R-type, I-type |
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R-type: register |
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addu $r10,$r8,$r9 # add 2 numbers |
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000000 |
01000 |
01001 |
01010 |
00000 |
100001 |
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b31-26 |
b25-21 |
b20-16 |
b15-11 |
b10-6 |
b5-0 |
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opcode |
$rs |
$rt |
$rd |
shamt |
function |
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3 registers: 2 source, 1
destination |
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operation: opcode and
function |
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I-type:
immediate |
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addi $rt, $rs, immed # add a constant to a register |
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001000 |
01000 |
01001 |
01010 |
00000 |
100001 |
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b31-26 |
b25-21 |
b20-16 |
b15-0 |
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opcode |
$rs |
$rt |
immediate |
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semantics: |
R[t] = R[s] + (IR15)16::IR15-0 |
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- sign-extend the immediate value to 32
bits |
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- add it (using signed addition) to
register R[s] |
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- store the result in register R[t] |
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