1. Access permission circuitry, comprising: first access protection circuitry which stores first access permission information corresponding to a first bus master; second access protection circuitry which stores second access permission information corresponding to a second bus master; access modification circuitry, coupled to the first and second access protection circuitry; and an access allowed indicator provided by the access modification circuitry, wherein in response to a first access by the first bus master, the access modification circuitry receives first state information and receives the first access permission information, wherein based upon the first state information, the access modification circuitry selectively modifies the first access permission information to produce first modified access permission information, wherein the first modified access permission information is used to determine whether the access allowed indicator will allow the first access; wherein in response to a second access by the second bus master, the access modification circuitry receives second state information and receives the second access permission information, wherein based upon the second state information, the access modification circuitry selectively modifies the second access permission information to produce second modified access permission information, and wherein the second modified access permission information is used to determine whether the access allowed indicator will allow the second access.