Page 404 - A Practical Guide from Design Planning to Manufacturing

374 Glossary

PLCC Plastic leaded chip carrier.
Plug and Play (PnP) A hardware and software specification that allows a com-
puter system to automatically detect and configure new components.
PMOS P-type metal oxide semiconductor field-effect transistor.
P-N junction The boundary formed between regions of P-type and N-type
semiconductors.

PnP Plug and Play
Pollack’s rule The observation that for processors using the same fabrication
technology, performance improves roughly with the square root of added die area.
Polycrystalline silicon (poly) Microscopic silicon crystals randomly oriented
and fused into a single piece. Commonly heavily doped and used as the gate ter-
minal of a MOSFET.
POST Power on self test.
Post-silicon validation The task of proving an integrated circuit design is log-
ically correct and meets all the product specifications by testing manufactured
chips.
Power bug A design flaw that causes an integrated circuit to use more power
than intended in executing a program but still produce the logically correct result.
Power on self test (POST) Initialization and diagnostics routines run when
a computer system is first turned on.
PowerPC A RISC computer architecture created by IBM and Motorola.
PQFP Plastic quad flat pack.
PR Photoresist.
Prepreg Fiberglass sheets that have been impregnated with epoxy resin but
not yet fully cured. These flexible sheets are used to separate interconnect
layers in multilayer packages and PCBs.
Pre-silicon validation The task of proving an integrated circuit design is log-
ically correct and meets all the product specifications by performing simulations
before the design is manufactured.
Printed circuit assembly (PCA) A printed circuit board with components
attached.
Printed circuit board (PCB) Rigid sheets of insulator and conducting wires (also
called traces) used to physically support and provide electrical connections between
electronic components. Most PCBs uses sheets of fiberglass and copper traces.
Proliferation design An integrated circuit design that reuses some elements
of a previous design but makes large logic changes and uses a new manufac-
turing process.
PSM Phase-shift mask.