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19. Simplified Instruction Encoding (not x86!)


  • Three high-order bit field, iii, defines the instruction and allows 8 unique bit combinations.

  • (Since we decided to encode 20 different instructions, we cannot encode them with three bits, so we'll have to pull some tricks to handle all of the instructions.)

  • Consider one-byte opcode with an optional two-byte constant value:

      simplified instruction encoding

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