Glossary
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switchless device
devices that do not require dip switches or jumpers to configure resources
on the devices—also called Plug and Play devices
synchronous
(1) hardware—a property of an event that is synchronized to a reference
clock; (2) software—a property of a function that begins an operation and
returns only when the operation is complete
system noise
a measure of the amount of noise seen by an analog circuit or an ADC when
the analog inputs are grounded
T
THD
total harmonic distortion—the ratio of the total rms signal due to harmonic
distortion to the overall rms signal, in decibel or a percentage
THD+N
signal-to-THD plus noise—the ratio in decibels of the overall rms signal to
the rms signal of harmonic distortion plus noise introduced
transducer
See
transfer rate
the rate, measured in bytes/s, at which data is moved from source to
destination after software initialization and set up operations; the maximum
rate at which the hardware can operate
TRIG1 (EXT_TRIG)
trigger 1 signal
trigger
any event that causes or starts some form of data capture
tri-state
logic circuitry designed to have three possible outputs—0, 1, and hi-Z. The
hi-Z (high impedance) state effectively pulls the output out of its circuit,
and can be used to simplify bus communication by wire-ANDing tri-state
inputs.
TTL
transistor-transistor logic
TTL-compatible
operating in a nominal range of 0 to 5 VDC, with a signal below 1 V a logic
low, and a signal above 2.4 V a logic high
two’s complement
format
a system for digitally encoding sound that stores the amplitude values as a
signed number, with silence represented by a sample with a value of 0. For
example, with 8-bit sound samples, two’s complement values would range
from –128 to 127, with 0 meaning silence.
See
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