National Instruments 6023E, 6024E, 6025E Programmable Peripheral Interface (PPI)

Chapter4 SignalConnections
6023E/6024E/6025EUser Manual 4-22 ni.com
Figure4-11. DigitalI/O Connections Block Diagram
Programmable Peripheral Interface (PPI)
♦6025E only
The 6025E deviceuses an 82C55A PPI to provide an additional 24 lines
ofdigital I/O that represent three 8-bit ports—PA, PB, and PC. Youcan
programeach portas an input or output port.
In Figure 4-11, port A of one PPI is configured for digital output, and
port B is configuredfor dig ital input. Digital input applications include
receivingTTL signals and sensing external device states such as the state
of the switch in Figure 4-11. Digital output applications include sending
GND
DIO Device
Switch
I/OConnector
+5V
+5V
LED
Port B
PB<7..4>
Port A
PA<3..0>
TTLSignal