Idle-element prediction circuitry and anti-thrashing logic

Abstract

Control logic monitors use of a particular functional element (e.g., a divider, or multiplier or the like) in a programmable processor, and the control logic powers the unit down when it has not been used for a specified time period. A counter (local or central) and time threshold determine when the period has elapsed without use of the element. The control logic also monitors how soon the functional unit is woken up again, to determine if power control is causing thrashing. Upon the determination of such thrashing, the unit automatically adjusts its threshold period, to minimize thrashing. In an example of the logic, when it determines that it is being too conservative, it lowers the threshold. Mode bits may allow the programmer to override the power-down logic to either keep the logic always powered-up, or always powered-down.

Description

technical field [0001] The present teachings relate to techniques and processor architectures that efficiently provide complex processing logic with reduced power consumption when the processing function requires less than full processing capability. Background technique [0002] Many devices utilize integrated processors, such as microprocessors and digital signal processors, with complex logic arrangements for implementing data processing functions in accordance with programmed instructions. Many applications of these processors (for example in portable devices with battery power) ensure fine control over power consumption (usually) to extend the charge life of the battery power. Many functions or applications of the processor do not require the full processing power of the processor device, or only require the full processing power for a very limited time. However, if continuously fully powered, unused logic consumes power unnecessarily. [0003] Traditionally, compleme...

AI Technical Summary

Problems solved by technology

However, there are situations where time-based power down of logic elements can be problematic

Waking up or powering up said components can cause additional power consumption

In some cases, powering up the element consumes more power than just leaving the element on for a short period of time

Also, time is required to drive components to standby

The resulting delay or delay in restarting the component can cause the processor to stall, which degrades performance

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