National Instruments PCI-1200 Manual De Usuario

© National Instruments Corporation

Use the handshaking lines STB* and IBF to synchronize input transfers. 
Use the handshaking lines OBF* and ACK* to synchronize output 
transfers.

The following signals are used in the mode timing diagrams: 

Table 3-6.  Signal Names Used in Timing Diagrams

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 primarily an input 
acknowledge signal.

ACK*

Input

Acknowledge Input—A low signal on this handshaking line indicates 
that the data written from the specified port has been accepted. This 
signal is primarily a response from the external device that it has 
received the data from the PCI-1200.

OBF*

Output

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

INTR

Output

Interrupt Request—This signal becomes high when the 82C55A is 
requesting service during a data transfer. Set the appropriate interrupt 
enable signals to generate this signal.

RD*

Internal

Read Signal—This signal is the read signal generated from the PCI 
interface circuitry.

WRT*

Internal

Write Signal—This signal is the write signal generated from the PCI 
interface circuitry.

DATA

Bidirectional

Data Lines at the Specified Port—This signal indicates when the data 
on the data lines at a specified port is or should be available.