Brookshear machine, instruction set and machine code 11-03-2019 PDF

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Summary

Lecture notes - Lecturer: John Carroll...

Description

The Brookshear Machine -Simpler than (most) real CPUs -However, instruction set shows main characteristics of RISC architecture -Has 16 registers (modern Intel CPUs also do), number 0 to F (hex) -Main memory has 256 locations, numbered 0 to FF

-Each register and memory location holds 1 byte -1 byte (8 bits) can be represented by two hex digits -Uses 16-bit instructions, so each is 2 bytes long and occupies two memory locations

Brookshear machine instruction format -Instructions are 16 bits long -Opcode: takes up first 4 bits, identifies type of instruction -Operands: take up remaining 12 bits;they are parameters, specifying what data the instruction should process (e.g. registers, memory addresses, bit patterns) -In hex, first digit represents opcode, other three represent operands...