RS-232/422/485 Filter Interrupt Reason (Composite)

RS-232/422/485 Filter Interrupt Reason block


Simulink® Real-Time™ Library for RS-232


The Filter Interrupt Reason block filters the output of the Read Int(errupt) Status block.

If the condition that the interrupt query block reads from the IIR register matches the one specified here, the output is true.

This block is used exclusively inside the interrupt service subsystem for this board.

The Commtech/Fastcom and Quatech® boards and blocks will be removed in a future release. Do not use them in new models. Instead, use boards and blocks available from

Block Parameters


From the list, choose a port. This parameter specifies the port from which this block gets control data.

Filter value

From the list, choose Receive data, Transmitter empty, or Modem status change. This parameter specifies the interrupt reason that this filter block is looking for.

Note that Modem status change currently does nothing because the interrupt is not enabled.

Introduced before R2006a

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