National Instruments 653X User Manual page 131

G
group
H
handshaking I/O
I
interrupt
I/O
K
k
L
line
LSB
low/high
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A collection of one, two, or four ports and an associated timing controller.
All buffered operations must be performed on groups.
Data-transfer mode in which the 653X device engages in a two-way
communication with the peripheral device. The 653X asserts a signal, ACK,
when it is ready for a data transfer and the peripheral device asserts a
separate signal, REQ, when it is ready for a data transfer. Data is transferred
only when both the 653X and the peripheral device are ready.
a computer signal indicating that the CPU should suspend its current task
to service a designated activity
Input/Output—a transfer of data to/from a computer system involving
communications channels, operator interface devices, and/or data
acquisition and control interfaces
Kilo—the standard metric prefix for 1,000, or 10
measure such as volts, hertz, and meters
Individual digital bit
Least significant bit
Refers to the active, or "on" state of handshaking I/O lines. For example, if
ACK is active low, the 653X device is ready when its ACK line asserts
(changes to) low.
G-5
Glossary
3
, used with units of
653X User Manual