SCENARIOS

SCENARIO

SCENARIO = MODE + CORNER.

MODE: MODE IS DEFINED AS A SET OF CLOCKS , SUPPLY VOLTAGES ,TIMING CONSTRAINTS AND LIBRARIES.

MODES TYPE:

1. FUNCTIONAL MODE.
2. TEST MODE.
3. RV MODE

                        _____________ HIGH

                        |

   MODES   --- _____________ LOW

                        |
                        ______________ NOMINAL
                                                    

IT CONTAINS SDC CONSTRAINTS.
IN DESIGN DIFFERENT FUNCTIONALITY MODES CONTAINS DIFFERENT SDC'S.
IN DESIGN DIFFERENT FUNCTIONALITY MODES ARE PRESENT.

CONSTRAINTS IN TEST MODE WHILE THE CHIP IS A DEVICES UNDER TEST:

• TESTER CLOCK PERIOD AND CLOCK SOURCES.
• MODEL TESTER SKEW ON THE INPUT PORTS.
• DIFFERENT TIMING EXCEPTIONS.
• DIFFERENT SETUP/HOLD ON THE OUTPUT PORTS.
• THE SCAN CHAIN IS EXCERSIED IN TEST MODE.(NOT IN FUNCTIONAL MODE).

CORNERS:

CORNERS CONTAINS PVT'S.

                        _____________ BEST CASE CORNER

                        |

PVT -------------

                        |
                        ______________WORST CASE CORNER.
                                                    

FOR SETUP :

Arrival Path-------- |
                                 |--------------------->Max Dealys
Data path------------|

Reqired Path------------------------------->Min Delays


FOR HOLD :

Arrival Path-------- |
                                 |--------------------->Min  Dealys
Data path------------|

Reqired Path------------------------------->Min Delays



BEST CASE : --------->FASTEST<-------->MIN DELAYS<------->Early<-----------> FOR HOLD

• MIN DELAYS IN ARRIVAL PATH,DATA PATH .
• MAX DELAYS IN CLOCK PATH.

PVT:   PROCESS---------------------->FAST

           VOLTAGE--------------------->HIGH

           TEMPERATURE------------>LOW

WORST CASE: --------->SLOWEST<-------->MAX DELAYS<------------> FOR SETUP

• MAX DELAYS IN  ARRIVAL PATH, DATA PATH.
• MIN DELAYS IN CLOCK PATH.

PVT:   PROCESS-------------------->SLOW

            VOLTAGE-------------------->LOW

            TEMPERATURE----------->HIGH