Mobile communication device having a prioritized interrupt controller

A system for use in a mobile communications device, said system comprising:

• a microprocessor having components for responding to interrupt requests by interrupting current processing and performing an interrupt service routine associated with the interrupt request;
• peripheral processing units having components for generating interrupt requests for sending to the microprocessor;
• and
• an interrupt controller having:
• means for receiving interrupt requests directed to the microprocessor, said interrupt request requesting the microprocessor to interrupt current processing and perform an interrupt service routine associated with the interrupt request;
• means for identifying an interrupt request of highest priority from among the interrupt requests received;
• and
• means for notifying the microprocessor of the interrupt request of highest priority,
• wherein said means for notifying the microprocessor includes:
• interrupt storage means for storing a value representative of the interrupt request of highest priority;
• and
• means for transmitting a notification signal to the microprocessor indicating that a new interrupt request is stored in the interrupt storage means,
• wherein the microprocessor includes:
• means for receiving the notification signal;
• interrupt access means for reading the value representative of the new interrupt request stored within the interrupt storage means;
• means for saving a current context of the microprocessor;
• means for determining whether a current interrupt service routine is being executed and, if so, for storing the interrupt request associated therewith in an interrupt stack;
• means for executing an interrupt service routine associated with the new interrupt request value read form the interrupt storage means;
• means for detecting completion of the interrupt service routine;
• and means for determining whether the interrupt storage means of the interrupt controller contains another value representative of an interrupt request and, if so, for executing an interrupt service routine associated with the interrupt request value read from the interrupt storage means and, if not, for retrieving an interrupt request, if any, stored at the top of the interrupt stack and the context saved in the means for saving a current context and for resuming execution based upon that context.

A method for use with an interrupt controller and a microprocessor within a mobile communications device, said microprocessor including components for responding to interrupt requests by interrupting current processing and performing an interrupt service routine associated with the interrupt request, said method comprising the steps of:

• receiving interrupt requests directed to the microprocessor using the interrupt controller;
• identifying an interrupt request of highest priority from among the interrupt requests received, using the interrupt controller;
• notifying the microprocessor of the interrupt request of highest priority in
• storing a value representative of the interrupt request of highest priority in an interrupt storage device;
• transmitting a notification signal to the microprocessor indicating chat a new interrupt request is stored in the interrupt storage means;
• receiving the notification signal;
• reading the value representative of the new interrupt request stored within the interrupt storage device;
• saving a current context of the microprocessor;
• determining whether a current interrupt service routine is being executed and, if so, storing the interrupt request associated therewith in an interrupt stack;
• executing an interrupt service routine associated with the new interrupt request value read from the interrupt storage device;
• determining completion of the interrupt service routine;
• and
• determining whether the interrupt storage device of the interrupt controller contains another value representative of an interrupt request and, if so, executing an interrupt service routine associated with the interrupt request value read from the interrupt storage device and, if not, retrieving an interrupt request, if any, stored at the top of the interrupt stack and the context associated therewith and resuming execution based upon that context.