8. 1 Background ●●● ●●●● ●●●●● ●●●● ●●0●● Memory is central to the operation of a. ●●●● modern computer system o Main memory and registers are only storage CPU can access directl Program must be brought (from disk) into memory e Instruction-execution cycle CPU fetches an instruction from memory according to the value of the program counter o The instruction is then decoded and may cause operands to be fetch from memory After the instruction has been executed the results may be stored back in memory4 8.1 Background ⚫ Memory is central to the operation of a modern computer system ⚫ Main memory and registers are only storage CPU can access directly ⚫ Program must be brought (from disk) into memory ⚫ Instruction-execution cycle ⚫ CPU fetches an instruction from memory according to the value of the program counter ⚫ The instruction is then decoded and may cause operands to be fetch from memory ⚫ After the instruction has been executed, the results may be stored back in memory