Control of the processor

Control of the processor

1. Functional requirements

   • decomposed the functioning of the processor into elementary operations
     • The basic elements of the processor are the following
       • Control unit
         • The control unit performs two basic tasks
         • Sequencing
         • Execution
       • External data paths
       • ALU
       • Registers
       • Internal data paths

2. Control Signals

   • We have defined the elements that make up the processor(ALU, registers,data paths) and the micro-operations that are performed.
   • INPUTS
     • Clock
     • Instruction register
     • Control signals from control bus
     • Flags
   • OUTPUTS
     • Control signals within the processor
     • Control signals to control bus

3. Internal processor organization

4. The Intel 8085

   • Incrementer/ decrementer address latch
   • Serial I/O control
   • Interrupt control