The wheni command executes commands when a specified low-level event occurs. It is valid only in native mode.
wheni event-specification [modifier]{command... ; }
When the specified event occurs, the commands are executed.
The following specific syntax is valid:
Execute command when address is reached.
where:
address is any expression resulting in or usable as an address.
command is the name of a command.
For a list and the syntax of all events see Setting Event Specifications.