A LOW-COST DIGITAL SCALABLE VOLTAGE-FREQUENCY ADJUSTOR DESIGN WITH LOW-POWER VIDEO DECODER SYSTEM VALIDATION

摘要

The proposed low-cost, synthesizable, scalable Voltage-Frequency Adjustor (VFA) design provides automatic voltage and frequency adjustment with stabilization mechanisms. This design is effective in reducing power consumption for dynamic varying systems. The supplied electrical current amount and voltage levels are automatically adjusted by sensing the voltage level from a fanout target designed circuit. If the fanout volta ge level is lower or higher than a preset value, the voltage stabilization mechanism is enabled by using a feedback control circuit. The voltage stabilization mechanism controls the activating power switch module quantity to allow a circuit module dynamically varied design that can obtain a stable fanin power, regardless of the designed module which is frequently added or removed from the system. Compared to the conventional dynamic voltage frequency scaling and DC-DC converter techniques, the VFA is cost effective and can be easily integrated with the target design as a single chip. The final experimental results are successfully validated, the H.264 decoder chip joining with two VFA chips has a range of 49%～68% power reduction compared to when the H.264 video decoder directly uses an external power supply.