5.4.12. PS2Keyboard component

The PS2Keyboard component is a virtual component that translates a stream of key press information into appropriate PS/2 serial data. The key press data stream must be provided from another component such as a visualization component.

Figure 5.33 shows a view of the component in System Canvas.

Figure 5.33. PS2Keyboard in System Canvas

PS2Keyboard in System Canvas

This component is written in LISA+.


Table 5.51 provides a brief description of the ports in the PS2Keyboard component. For more information, see the technical reference manual for your hardware baseboard.

Table 5.51. PS2Keyboard ports

NamePort protocolTypeDescription
keyboardKeyboardStatusSlaveReceives keyboard input from, for example, the Visualisation component.
clk_inClockSignalSlaveDrives the PS/2 clocking rate, typically 1MHz.
ps2PS2DataMasterConnection to the PS/2 controller, for example, the PL050_KMI.


The PS2Keyboard component has one additional protocol.

The KeyboardStatus protocol is used to pass keyboard events to a component such as the PS2Keyboard component. Events are only sent when the visualization window is in focus. Keyboard combinations which are filtered by the host OS such as Ctrl+Alt+Del are not detected by the visualization. See components/KeyCode.h for a list of ATKeyCode code values.

The protocol behaviors are:

keyDown(ATKeyCode code) : void

This is sent when a key on the host keyboard is pressed.

keyUp(ATKeyCode code) : void

This is sent when a key on the host keyboard is released.


The PS2Keyboard component has no parameters.


The PS2Keyboard component has no registers.

Debug features

The PS2Keyboard component has no debug features.

Verification and testing

The PS2Keyboard component has been tested as part of the VE example system using VE test suites and by booting operating systems.


The PS2Keyboard component is not expected to significantly affect the performance of a PV system. However if it is connected to the Visualisation component, then the performance of the component is dependent on that of the visualization.

Library dependencies

The PS2Keyboard component has no dependencies on external libraries.

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