J277 Computer Science 1.1 System Architecture

The --- holds the address of the next instruction in memory

Currently running software is stored in --- ?

RAM is

• volatile - read only

• volatile - write only

• volatile - read and write

• dangerous if you upset it

The role of the ALU is ...

• to carry out calculations

• to carry out logic comparisons

• to carry out calculations and instructions

• to carry out calculations and logic comparisons

ROM

• stores data and is volatile

• stores data and is non-volatile

• is volatile

• is non-volatile

The speed of a CPU is measured in ---?

Cache is ...

• ... very fast memory, faster than registers, low capacity

• ... very fast memory, slower than registers,

  low capacity

• very fast memory, faster than registers, high capacity

• very fast memory, slower than registers, low capacity

During the Fetch section of the Fetch Decode Execute Cycle

• Copy Memory Address from the Program Counter to the MAR

• write data to memory

• the instruction in the MDR is decoded by the CU

• the cache is checked to see if the data needed is there, if not it will fetch it from RAM

During the Decode section of the Fetch Decode Execute Cycle

• Copy Memory Address from the Program Counter to the MAR

• write data to memory

• the instruction in the MDR is decoded by the CU

• the cache is checked to see if the data needed is there, if not it will fetch it from RAM

During the Execute section of the Fetch Decode Execute Cycle

• Copy Memory Address from the Program Counter to the MAR

• write data to memory

• the instruction in the MDR is decoded by the CU

• the cache is checked to see if the data needed is there, if not it will fetch it from RAM