Computer Science – 4.1 Central Processing Unit (CPU) Architecture | e-Consult

Maximum Addressable Memory: With a 32-bit address bus, the maximum amount of memory that can be directly accessed is 2³² bytes. This is equal to 4,294,967,296 bytes, or 4 GB. Therefore, the system can directly access 4GB of memory.

Impact of Data Bus Width on Performance: The data bus width significantly impacts system performance. A wider data bus allows more data to be transferred in a single clock cycle. This reduces the number of clock cycles required to complete a data transfer, leading to faster execution of instructions and improved overall system speed. For example, a 64-bit data bus can transfer twice as much data per cycle as a 32-bit data bus, assuming all other factors remain constant.

Sequence of Events for Reading Data from Memory:

1. The CPU places the memory address of the desired data onto the address bus.
2. The CPU asserts the Read signal on the control bus.
3. The memory controller receives the address and the Read signal.
4. If the memory is ready (MRD is asserted), the memory controller places the data stored at the specified address onto the data bus.
5. The CPU reads the data from the data bus.
6. The memory controller deasserts the Read signal.