- Major function of BIU is to fetch instruction data from memory and write data (result) back to memory.
- It also reads and writes data from Input/output ports.
- To perform memory operations it generates 20-bit physical address.
Functions of Execution Unit(EU)
Control system inside the execution unit controls all internal and external operations by sending control signals. This results in fetching Instructions and Data from memory.
It decodes and executes instructions fetched by Bus-Interface Unit.