DESIGN CHALLENGE-OPTIMIZING DESIGN METRICS
In Embedded systems the designer must ofcourse construct an implementataion that fulfills desired functionality,but a difficult challenge is to construct an implementation that simultaneously optimizez numerous design metrics.
Common Design Metrics:-
For our purpose,we are using microprocessor with an accompanying program,a connection of digital gates or some combination.Design metrics is the measurable feature of the system’s implementation.
Commonly used metrics:-
* JPEG(JOINT PHOTOGRAPHIC EXPERTS GROUP):-Joint refers to the group’s status as a committee working on both ISO and ITU-T standards.
* NRE COST(NONRECURRING ENGINEERING COST):-The one time monetary cost of designing the system.Once the system is designed any number of systems can be designed without any additional cost.
* UNIT COST:-The monetary cost of each copy of the system,without NRE Cost.
* SIZE:-The system required by the system,measured in bytes for software and gates for hardware.
* PERFORMANCE:-The working of the system.
* Power:-The power consumed by the system,which may determine the system lifetime.
* FLEXIBILITY:-The ability to make the changes without heavy change in the NRE Cost.
* TIME-TO-PROTOTYPE:-Time needed to built a working version of the system,which may be expensive than the final system,but it can be used to verify the system’s correctness.
* TIME-TO-MARKET:-Time required to develop the system within the time and sold to the consumer.
* MAINTAINABILITY:-Ability to modify the system after the system has entered into the market,especially by the designer who did not originally designed it.
* CORRECTNESS:-Designing of the test circuitry to show that the designed system was good.
* SAFETY:-The probability that the system will not harm.