Pin Watch – Monitor and control selected pins

The Pin Watch allows you to track the current state of selected pins and to create busses.

Displaying the Pin Watch

To display the Pin Watch, click View Pin Watch on the toolbar, or select Pin Watch from the View menu.

Adding Pins to the Pin Watch

To add pins to the Pin Watch:

• Drag one or more pins from the Pin List or Chain View.
• Right-click a pin in the Pin List or Chain View, and click Add to Pin Watch.
• Pins can also be added automatically when the Monitor Changing Pins or the Monitor Conflicts options are selected.

Pins can be automatically added to the Pin Watch by right-clicking in the Pin Watch pane and selecting one of the two options:

• Monitor Changing Pins – this option will automatically add any pin whose value changes.
• Monitor Conflicts – this option will automatically add any pin that goes into a conflicting state.

Conflicting pins will be discussed in more detail later in this tutorial.

Pin 22 of Device 1 is automatically added to the Pin Watch, as it is connected to the button.

Driving Pins

Pins can be driven from the Pin Watch in the same two ways as they can be driven from the Chain View:

• Right-click a pin to display the Pin Menu, and choose a value to drive the pin to.
• Double-click a pin to toggle its value. If a pin is being read high, double-clicking the pin will drive it low and vice-versa.

Creating a bus

The Pin Watch pane allows you to group pins together to form a bus. You can then drive values onto the bus rather than the individual pins.

To create a bus, right-click a pin in the Pin Watch pane and select Create Bus. You can then add further pins to the bus by dragging and dropping.

In order to use the bus it is sensible to rename it to reflect its function. In this case the bus allow two of the LEDs to be controlled.

Driving values onto a bus

The bus that you have just created controls two of the LEDs on the XJDemo board. To set the values for all the pins in the bus, right-click the bus and select Set Bus Value from the menu.

You can enter the bus value in decimal, hexadecimal, or binary: to enter a hex value, prefix the number with "0x"; to enter a binary value, prefix the number with "0b". The value will be converted into binary if necessary and driven onto the pins in the bus.

The value read back on a bus can also be displayed in hexadecimal, decimal or binary. To change the base in which the read value is displayed, right-click the bus and select Display Bus Values As from the menu.

XJDemo v4 lights its LEDs by driving low and turns them off by driving high. Setting a bus value of 3 will therefore turn off both LEDs, and 0 will light both.

Go to Pin

To highlight a particular pin in the Chain View, right-click any pin in the watch and select Go to Pin.