A thermal management design for system-on-chip circuits and advanced computer systems

Increases in circuit density and clock speed in modern VLSI designs have brought thermal issues into the spotlight of high-speed integrated circuit design. Local overheating in one spot of a high-density circuit, such as a CPU on high speed mixed-signal circuit, can cause a whole system to crash. Clock synchronization problems, parameter mismatching and other coefficient changes due to temperature gradients generated by uneven heat-up of on-chip circuitry are the major reasons for system failure. The early stage of this project has successfully characterized the local heat-up problem through an analytical model and test chip. The impact of temperature gradients on circuit behavior is also evaluated. Since the outcome of this analysis has proven the importance of this matter, a systematic solution to thermal management has been proposed. Instead of worst-case thermal management used in conventional systems, this design targets nominal power dissipation and requires the system to actively manage its thermal activity, including monitoring thermal activity and reacting to specified conditions through the control of cooling mechanisms, such as an integrated multi-stage fan controller, to ensure operation within specification. Continuing work includes further improvement in the circuit and architecture as well as analyzing and optimizing the performance of this design. The limitations and advantages by using this thermal management design are also assessed to establish guidelines for designing and analyzing modern system-on-chip designs, which are often limited by thermal factors because of inherent power density and sizes. The success of this project offers an opportunity for modern system-on-chip designs to incorporate thermal management techniques to enhance system stability and performance. This design yields intricate control and optimal management with little system overhead and minimum hardware requirements, as well as provides the flexibility to support different management algorithms.