National Instruments 3.21E+04 用户手册

Chapter 4     Signal Connections

AT-MIO/AI E Series User Manual

4-54

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 National Instruments Corporation

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.

STB*

input

Strobe Input—A low signal on this handshaking line loads data into the input 
latch.

IBF

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.

ACK*

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.

OBF*

output

Output Buffer Full—A low signal on this handshaking line indicates that 
data has been written from the selected port.

INTR

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.

RD*

internal

Read Signal—This signal is the read signal generated by the host computer.

WR*

internal

Write Signal—This signal is the write signal generated by the host computer.

DATA

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.