Research And Implementation On Low Power Design Of Embedded System

The purpose of low power design is to minimize the energy consumption of an embedded system and extend the lifetime of battery without losing its performance. With the developing requirement in size and performance of embedded devices from the market, the gap between small size, high performance and the limited battery life has become more and more wide, low power design of embedded system is an efficient approach to solve that problem. Low power design of embedded system consists of two parts: one is low power design of hardware and the other one is low power design of software.The purpose of low power design of hardware is to give a hardware support to optimize the energy consumption of whole system. Low power design of hardware at circuit level focuses on low power character of processor and peripherals, designs the power supply circuit of processor and peripherals: the processor's power supply circuit can dynamically change it's output voltage, it allows processor to change its input voltage according to its clock frequency; the peripherals' power supply circuit allows processor to control peripherals' power supply, from this we can restrict energy consumption of the peripherals.The goal of low power design of software is to realize an efficient power management mechanism, and the adoptive technology or algorithms do not change the schedule policy of Linux. The main work includes: adding dynamic voltage scaling to embedded Linux, based on the characters of processor, which can dynamically change its speed and voltage; adding dynamic power management to embedded Linux, according to the different work modes of processor, from this we can control the processor to sleep or wake up at the right time; realizing a control mechanism of peripherals in embedded Linux, including acquiring the information of peripherals, operations that put them into sleeping or waking up and the related management policy.