HP 9112 4.4Digital Input and Output

4.4Digital Input and Output

The PCI-9112 provides 16 digital input and 16 digital output channels through the connector CN1 and CN2 on board. The digital I/O signal are fully TTL/DTL compatible. The detailed digital I/O signal are specified in section 1.3.

To program digital I/O operation is fairly straight forward. The digital input operation is just to read data from the corresponding registers, and the digital output operation is to write data to the corresponding registers. The digital I/O registers‘ format are shown in section 4.5. Note that the DIO data channel can only be read or written in form of 16 bits together. It is impossible to access individual bit channel.

74LS244	Digital Input(DI)
	From TTL Signal
	Digital Output (DO)
	To TTL Devices
74LS373	Digital GND (DGND)

ACL-8112 Outside Device

Figure 4.4 Digital I/O Connection

34 ∙ Operation Theorem