Timing

Notes on creating a device timing model

Fanout effect timing info. IIRC I saw about 20% variation across things

Node

SPEED_CLASS shifts around a lot depending on other parameter values, which also shift around

A few interesting comparisons

• SPEED_CLASS difference
  • BASE_CLOCK_REGION:X0Y3 CLASS:node COST_CODE:21 COST_CODE_NAME:HQUAD IS_BAD:0 IS_COMPLETE:1 IS_GND:0 IS_INPUT_PIN:0 IS_OUTPUT_PIN:0 IS_PIN:0 IS_VCC:0 NAME:INT_L_X0Y199/WW4BEG3 NUM_WIRES:13 PIN_WIRE:65535 SPEED_CLASS:100
  • BASE_CLOCK_REGION:X0Y3 CLASS:node COST_CODE:21 COST_CODE_NAME:HQUAD IS_BAD:0 IS_COMPLETE:1 IS_GND:0 IS_INPUT_PIN:0 IS_OUTPUT_PIN:0 IS_PIN:0 IS_VCC:0 NAME:INT_L_X2Y199/WW4BEG3 NUM_WIRES:13 PIN_WIRE:65535 SPEED_CLASS:284
  • Everything is basically the same, but speed class is still different

PIN_WIRE: sometimes 65535

The following fields are consistent across (site type, wire name) tuples:

• SPEED_CLASS
• COST_CODE
• COST_CODE_NAME
• IS_BAD
• IS_COMPLETE
• IS_GND
• IS_VCC