TIMING AND CONTROL UNITS

ARCHITECTURE

TIMING AND CONTROL UNITS

1. it has three control signals ALE , RD (active low ) and WR (active low ) and status signals IO/M(m bar) , S0,S!.
2. ALE is used for provide control signal to synchronized the components of micro-processor and timing for instruction to perform the operation

3 RD (read RD bar) (active low) and WR (active low) are used to indicate whether

The operation is reading the data from memory or writing the data into memory

Respectively

4 IO/M (m bar) (active low) is used to indicate whether the operation is being to

the memory or peripherals

FUNCTIONS OF MICRO-PROCESSOR

Ø The various functions performed by the micro-processor can be classified as

o Micro-processor – initiated operation

o Internal operation

o Peripherals or ( externally initiated ) operations

MICRO-PROCESSOR INITIATED OPERATIONS

Micro-processor perform primarily four operations

• MEMORY READ : read data ( or instruction ) from the memory

• IO/READ : accept data from i/o device

• Identify the peripheral or memory location ( with it’s address )

• Transfer binary information ( data and instruction )

• Provide timing and synchronization slag

This all perform are performed in 3 clock

INTERNAL OPERATIONS

• store 8 bit data
• perform arithmetic and logical operation
• test for condition
• sequence the execution of instruction
• store data temporarily during execution in the defined read / write memory location called stacks

PERIPHERAL OR EXTERNALY INITIATED OPERATION

External signal or device can initiated following

• RESET
• INTERUPT
• READY
• HOLD

Labels: Intel Micro-Processors