Term | Meaning | Taught in |
|---|---|---|
Ball-out | The assignment of signals to package balls, reviewed for supply spread, signal pairing and board routing. | |
Decoupling hierarchy | Capacitance at each level, from on-die to package to board, each covering a different frequency range. | |
Drive strength | The current an output pad can source or sink. Stronger drive switches faster but adds supply noise. | |
Escape routing | Getting signals from inner package balls out to the board. It limits how a ball-out can be arranged. | |
ESD protection | Structures that conduct electrostatic discharge away from the core. Their paths must work between every pair of pads and supplies. | |
I/O ring | The ring of pads and their cells around the die, carrying signals, supply and protection. | |
Latch-up | A parasitic structure that shorts the supply when triggered. The guard rings and spacing rules at the pad-to-core interface prevent it. | |
Pad reset state | What each pad does while reset is asserted: input, output, pull. A bad state can fight an external driver. | |
Rail sequencing | The order in which supplies rise and fall, so no domain is driven before its supply is valid. | |
Signal and supply pad budget | How many pads carry signals and how many carry power and ground. Too few supply pads makes simultaneous switching noise worse. | |
Simultaneous switching noise (SSN) | Supply bounce when many outputs switch together, estimated from the current step, the loop inductance and the number of outputs. |
Back to the Glossary for the other groups and the look-alike terms.