I/O Port Write

Write Intel 80x86 I/O port (not recommended)


Simulink® Real-Time™ Library of Drivers No Longer Recommended for Use


Intel® 80x86 and compatible processors have a special address space reserved for I/O devices.


To access this special address space and communicate directly to a device, the Simulink Real-Time block library provides the I/O Port Read and I/O Port Write blocks. These blocks enable the transfer of data from and to the I/O ports (see I/O Port Read).

  1. Double click the I/O Port Write block.

    The Block Parameters: I/O Port Write dialog box opens.

  2. Enter the parameters.

    For example, if you want to write a double word (32 bits) starting at I/O port 0x300, followed by a word (16 bits) at 0x304, enter

  3. Click OK.

    The number of inputs to the block changes to reflect the length of the I/O-Port address cell array. The data type of the input signal reflects the type of value written to the I/O port. For example, an input signal of type uint32 writes a double word, an uint16 input signal writes a word, and an uint8 input signal writes a byte.

Block Parameters

I/O-Port address (cell array)

This is the cell array containing the I/O port addresses for the data that you want read. These addresses are specified in terms of hexadecimal character vectors.

Sample time

Enter the base sample time or a multiple of the base sample time (-1 means sample time is inherited).

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