SERIAL BUS CONTROL METHOD AND
APPARATUS FOR A MICROELECTRONIC
POWER REGULATION SYSTEM
CROSS-REFERENCE TO RELATED 5
This application claims priority to, and the benefit of, U.S. Provisional Patent Application Serial No.: 60/297,679, entitled "SERIAL BUS CONTROL SCHEME FOR A POWER REGULATOR SYSTEM" and filed on Jun. 12, 10 2001; and is a continuation in part of U.S. Non-Provisional Patent Application Serial No.: 10/104,039, entitled "POWER REGULATION SYSTEM, APPARATUS, AND METHOD FOR PROVIDING REGULATED POWER TO A MICROELECTRONIC DEVICE" and filed on Mar. 22, 15 2002 which are hereby incorporated by reference in their entirety.
The present invention generally relates to microelectronic power regulation systems and components. More particularly, the invention relates to a serial bus control scheme suitable for providing communication between various portions of a microelectronic power regulation system. 2J
Microelectronic power regulation systems generally include a power regulator configured to supply a desired, regulated power to a microelectronic device such as 30 microprocessors, microcontrollers, memory devices, and the like. The system may also include capacitors located near and/or packaged with the microprocessor to supply additional charge during the operation of the microprocessor. Such power regulation systems are configured so that the 35 power regulator (e.g., a switching regulator such as a Buck regulator) provides nominal operating power to the microprocessor and the capacitors supply charge to compensate for transient power demands that result from operation of the microelectronic device. Such transient power demands may 40 occur, for example, when several transistors of the microprocessor switch in the same direction at approximately the same time—e.g., when a portion of the device is powered off to conserve power or a portion of the device is activated.
As the speed and integration of microprocessors increase, 45 the use of power regulation systems that only employ decoupling capacitors to compensate for or regulate transient power demands becomes increasingly problematic. For example, the number and/or size of the capacitors required to account for transient events generally increases as the 50 integration of the microprocessor increases. The capacitors take up a relatively large amount of space on the package and can be relatively expensive. In addition, as the speed and the performance of the microprocessor increases, the severity (e.g., the amplitude) of the transient power demands and 55 the frequency of the events tend to increase. Further, the microelectronic devices often become more sensitive to degraded power waveforms, which result from transient events, as the integration and speed of the devices increase. Capacitors within typical power regulation systems may be 60 unable to adequately regulate such sever transient power demands. If not regulated or filtered, transient power events may result in a power or ground "spike" or "bounce"—i.e., momentary voltage levels below or above the nominal operating voltage of the microelectronic device, which in 65 turn induces bit errors in digital logic of the microelectronic device through degraded noise margin and supply-induced
timing violations. Accordingly, improved apparatus for responding to transient events that result during operation of a microelectronic device are desired.
Furthermore, although typical Buck regulators are generally suitable for controlling power to some microprocessors, such regulators are not well suited to supply relatively high current (e.g., greater than about 30 amps) at relatively high speed (e.g., greater than about 100 kHz). One reason that Buck regulators have difficulty supplying high current at high speed to the microprocessor is that the regulator is configured to supply a single core operating voltage (Vcc) to the entire microprocessor. Supplying power from a single source and distributing the power to a limited number of locations of the microprocessor may be problematic in several regards. For example, various portions of the microprocessor may operate more efficiently at different amounts of power—e.g. at different current and/or voltage levels. To compensate for the different power requirements, the microprocessor may require additional components and integration to step the power up or down as needed. Such additional components and integration may undesirably add to the cost and complexity of the microprocessor and systems including the microprocessor. Further, supplying all or most of the power from a single regulated power source requires a relatively large power regulator, which is generally inherently slow to respond to changes in power demands.
Another problem associated with supplying the same operating power to a limited number of locations of a microprocessor is that microprocessor wiring schemes configured to distribute the regulator power to the microprocessor are generally complex and include relatively long wiring sections to supply power to sections of the device located away from the input source of the power. The relatively long wiring sections may cause delay and undesirable signal degradation or loss of the transmitted power. Accordingly, improved methods and apparatus for providing power to a plurality of portions of a microelectronic device and to supply various amounts of power to a plurality of locations on the microprocessor are desired.
SUMMARY OF THE INVENTION
The present invention provides improved apparatus and techniques for transmitting signals between portions of a microelectronic power regulation system.
While the way in which the present invention addresses the disadvantages of the prior art will be discussed in greater detail below, in general, the present invention provides a power regulation system capable of detecting a transient event, communicating between portions of the power system, and responding to the sensed transient power event.
In accordance with one exemplary embodiment of the present invention, a power regulation system in accordance with the present invention includes one or more secondary or transient suppression regulators coupled to a microelectronic device and configured to respond to or account for high-frequency transient power demands and a controller coupled to at least one of the secondary regulators. In accordance with one embodiment of the invention, the controller is configured to periodically poll the secondary regulator and to write or send information to the secondary regulator based on the polled information.
In accordance with one embodiment of the invention, a secondary regulator includes a slave controller configured to receive information from a master controller and to send information to the master controller. In accordance with various aspects of this embodiment, a serial interface pro