Intel 87C196CA, Supplement To User’S Manual

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Glossary-9
GLOSSARY
PTS vector A location in special-purpose memory that holds the
starting address of a PTS control block.
QUAD-WORD An unsigned, 64-bit variable with values from 0
through 2
64
–1. The QUAD-WORD variable is
supported only as the operand for the EBMOVI
instruction.
quantizing error An unavoidable A/D conversion error that results
simply from the conversion of a continuous voltage to
its integer digital representation. Quantizing error is
always
±
0.5 LSB and is the only error present in an
ideal A/D converter.
RALU Register arithmetic-logic unit. A part of the CPU that
consists of the ALU, the PSW, the master PC, the
microcode engine, a loop counter, and six registers.
repeatability error The variation in code transitions when comparing a
number of actual characteristics from the same
converter on the same channel with the same temper-
ature, voltage, and frequency conditions. The amount
of repeatability error depends on the comparator’s
ability to resolve very similar voltages and the extent
to which random noise contributes to the error.
reserved memory A memory location that is reserved for factory use or
for future expansion. Do not use a reserved memory
location except to initialize it.
resolution The number of input voltage levels that an A/D
converter can unambiguously distinguish between.
The number of useful bits of information that the
converter can return.
sample capacitor A small (2–3 pF) capacitor used in the A/D converter
circuitry to store the input voltage on the selected
input channel.
sample delay The time period between the time that A/D converter
receives the “start conversion” signal and the time
that the sample capacitor is connected to the selected
channel.
sample delay uncertainty The variation in the sample delay.
sample time The period of time that the sample window is open.
(That is, the length of time that the input channel is
actually connected to the sample capacitor.)