National Instruments AT-MIO/AI E Series User Manual page 103

Chapter 4 Signal Connections
Name
STB*
IBF
ACK*
OBF*
INTR
RD*
WR*
DATA
AT-MIO/AI E Series User Manual
This section lists the timing specifications for handshaking with the
AT-MIO-16DE-10 port C circuitry. The handshaking lines STB* and
IBF synchronize input transfers. The handshaking lines OBF* and
ACK* synchronize output transfers.
The following signals are used in the timing diagrams that follow.
Type Description
input Strobe Input—A low signal on this handshaking line loads data into the input
latch.
output Input Buffer Full—A high signal on this handshaking line indicates that data
has been loaded into the input latch. This is an input acknowledge signal.
input Acknowledge Input—A low signal on this handshaking line indicates that
the data written from the selected port has been accepted. This signal is a
response from the external device that it has received the data from the
AT-MIO-16DE-10.
output Output Buffer Full—A low signal on this handshaking line indicates that
data has been written from the selected port.
output Interrupt Request—This signal becomes high to request service during a
data transfer. The appropriate interrupt enable bits must be set to generate
this signal and to allow it to interrupt your computer.
internal Read Signal—This signal is the read signal generated by the host computer.
internal Write Signal—This signal is the write signal generated by the host computer.
input or output Data Lines at the Selected Port (PA or PB)—This signal indicates when the
data on the data lines at a selected port is or should be available.
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