272Tibbo Project System (TPS)
© Tibbo Technology Inc.
TPP2 and TPP3 boards offer four "M" sockets with UART lines.
7.2.5.2
[INT] Tibbits That Require an Interrupt Line
Some Tibbits require an interrupt line. For example, on Tibbits #01 (simple RS232
port), #02 (universal RS232/422/485 port) the interrupt is used to detect state
changes on the CTS line. This is necessary for the RTS/CTS flow control. Obviously,
an RS232 port doesn't always need the flow control, so the interrupt line may not
be necessary. Other Tibbits, such as #08 (Wiegand and clock/data reader port)
must be wired to the interrupt line, or they won't be able to do their job.
The INT line, when present on a Tibbit, is always mapped into the control line D: