Line Mode Control
For all the I/O lines, the LineMode
feature reports the configuration of the I/O port.
Only the TTL I/O lines have a user-configurable line mode.
A TTLIO can operate as an input or as an output.
When used as input, no configuration is required since at power-up all TTLIO ports are configured as Inputs.
When used as output, the user has the choice between 3 configurations of the line driver. The line driver can be configured in 3 ways:
- As a totem-pole driver capable of driving low and high.
- As an open-collector driver capable of driving low only
- As an open-emitter driver capable of driving high only.
The two latest configurations allows wired-AND configurations.