µVision® IDE & Debugger

I/O Port Simulation

The µVision Debugger simulates the I/O ports found on many 8051, 251, 166, and ARM derivatives.

The dialog for each port allows you to change the values of the on-chip latches as well as the value asserted on each pin of the device.

You may change the values on the pins of a port using the debugger defined variable for that port.

For example, the following line:

PORT1 = 0xAA

when entered in the Command Window sets the value of the Port 1 pins. You may use bit-wise operators to set and clear specific pin states. For example:

PORT1 |=  0x01  /* Set P1.0 */
PORT1 &= ~0x01  /* Clr P1.0 */
PORT1 ^=  0x01  /* Toggle P1.0 */

The Blinky Example provides a demonstration of how to toggle the bits of an I/O Port. The output is shown in the Logic Analyzer output on the left.

This example is available in a configuration for each architecture supported by the µVision IDE/Debugger.