IBM has posted an application note in direct reference to a dual 64-bit core PowerPC970MP and how to use thermal diodes in the chip. This is the first known reference to a dual-core chip to be made by IBM in regards to the PowerPC 970 (otherwise known as Apple's G5 Processor). The article and reference gives credence to the recent rumors of UI changes to the Apple CHUD Developer tools, and MONster.app showing support for 4 processors.
The dual 64-bit core PowerPC970MP (970MP) is the next evolutionary step in the PowerPC 970 family of microprocessors. The higher frequency grade versions of the 970MP consume higher amounts of power than earlier IBM microprocessors do, and that can cause temperature issues. Each 970MP processor core contains a thermal diode used to monitor its operating temperature. The thermal diode must be monitored to ensure that the maximum operating temperature of the 970MP is not exceeded. These thermal diodes used by the microprocessors are unique to the PowerPC architecture and cannot be 'read' using standard thermal diode monitoring chips. This paper will discuss the characteristics of the diode and outline the struc-ture of a thermal diode monitoring circuit used to monitor the temperature of the microprocessors cores.
