1. A method of controlling a monitoring function of a processor, said processor being operable in at least two domains, comprising a first domain and a second domain, said first and second domains each comprising at least one mode, said method comprising the steps of: controllably monitoring said processor operating in each of said at least two domains, setting at least one control value to an enable value, said at least one control value relating to a condition, said condition consisting of a respective one of (a) a domain that said processor is operating in, or (b) a mode that said processor is operating in or (c) a type of said monitoring function, said control value being set to be an enable value for said related condition to indicate that said monitoring function is allowable in said first domain; allowing initiation of said monitoring function in said first domain when said condition is present if its related control value is set to said enable value and thereby indicates that said monitoring function is allowable; and not allowing initiation of said monitoring function in said first domain when said condition is present and its related control value is not set to said enable value and thereby indicates that said monitoring function is not allowable.