Documentation

RS-232/422/485 Read Int(errupt) Status (Composite)

RS-232/422/485 Read Int(errupt) Status

Library

Simulink® Real-Time™ Library for RS-232

Description

The Read Interrupt Status block reads the interrupt status for the boards in the system.

The output for this block is a vector with one 32-bit element for each port. Each element contains two pieces of information for that port, where the 4 bytes are:

[0, 0, IIR, Reason]

The Read Interrupt Status block has signal output with the following format:

This output is a vector of integers. The values in the reason byte and their definitions are:

  • 0 — This UART did not cause this interrupt.

  • 1 — Receive characters are available.

  • 2 — Transmit holding register is empty.

  • 3 — Modem status has changed (ignored).

The second byte is the value read from the Interrupt Reason Register (IIR). This register is specific to the 16450, 16550, and 16750 types of UARTs. Some bytes in this register give the active FIFO depth. Other bytes give the maximum number of characters that the transmitter empty interrupt handlers can write to the transmit FIFO.

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 www.speedgoat.com/products.

Block Parameters

Base address 1 (Mainboard, ISA boards)

Enter the base address of the first UART for which you want to read the interrupt status.

Base address 2 (Mainboard, ISA boards)

Enter the base address of the second UART for which you want to read the interrupt status.

Slot (PCI boards)

If only one board of this type is in the target computer, enter -1 to automatically locate the board.

If two or more boards of this type are in the target computer, enter the bus number and the PCI slot number of the board associated with this driver block. Use the format [BusNumber, SlotNumber]. To determine the bus number and the PCI slot number, type:

tg = slrt;
getPCIInfo(tg, 'installed')

Introduced before R2006a

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