Abstract: A method and apparatus for providing relocatable code storage in a multifunction controller or other integrated circuit which includes an embedded microprocessor and an internal memory. The relocatable code is initially stored in an external memory which is shared by the embedded microprocessor and other system processing elements such as a host CPU. During a system initialization, power-on reset or other predetermined event, a memory multiplexing circuit connects the address inputs of the internal memory to a read/write address bus, and connects the output of a jump data storage circuit to a code data output bus. The jump data storage circuit uses code addresses received from the embedded microprocessor to generate a jump instruction code which is supplied to the embedded microprocessor via the code data output bus.

Abstract: A method and apparatus for providing power management functions in a multifunction controller having an embedded microprocessor. An enter sleep mode indication is received in the microprocessor in the form of, for example, a command generated by a host central processing unit or an interrupt indicating a lack of system activity for a predetermined period of time. The clock input to the microprocessor is switched from a first clock source to a second clock source in response to the enter sleep mode indication. The main system supply may then be powered down by the microprocessor. The first clock source is then turned off after expiration of a first predetermined delay. The second clock is subsequently turned off after a second predetermined delay, to thereby place the system and the microprocessor into a sleep mode. While the system and microprocessor are in the sleep mode, an interrupt-handling portion of the microprocessor and a power control logic circuit remain powered off a low-current standby supply.

Abstract: A method is disclosed for giving a host CPU direct access to the address space of an embedded microprocessor in a multifunction controller. The data path of the multifunction controller chip is modified to enable this direct access.