Glossary-7
GLOSSARY
nonlinearity The maximum deviation of code transitions of the
terminal-based characteristic from the corre-
sponding code transitions of the ideal characteristic.
nonmaskable interrupts Interrupts that cannot be masked (disabled) and
cannot be assigned to the PTS for processing. The
nonmaskable interrupts are stack overflow, unimple-
mented opcode, software trap, and NMI. The DI
(disable interrupt service) and EI (enable interrupt
service) instructions have no effect on nonmaskable
interrupts.
npn transistor A transistor consisting of one part p-type material and
two parts n-type material.
off-isolation The ability of an A/D converter to reject (isolate) the
signal on a deselected (off) output.
p-channel FET A field-effect transistor with a p-type conducting
path.
p-type material Semiconductor material with introduced impurities
(doping) causing it to have an excess of positively
charged carriers.
PC Program counter.
phase-locked loop A component of the clock generation circuitry. The
phase-locked loop (PLL) and the input pin (PLLEN)
combine to enable the microcontroller to attain its
maximum operating frequency with an external clock
whose frequency is either equal to or one-half that
maximum frequency or with an external oscillator
whose frequency is one-half that maximum
frequency.
PIC Programmable interrupt controller. The module
responsible for handling interrupts that are to be
serviced by interrupt service routines that you
provide. Also called simply the interrupt controller.
PIH Peripheral interrupt handler. An integrated module
that provides interrupt vectors for specific EPA
interrupt requests to the interrupt controller or PTS.
PLL See phase-locked loop.