Design and Implementation of a USB Device Controller with the Power Management Unit

In this paper, the design and implementation of a strategy to reduce the power dissipation are presented for a USB Device Controller (UDC). The proposed strategy provides a specific power management unit (PMU) which can make the UDC switch into or out the standby mode in many ways by a suspend-wakeup mechanism. The detailed design of the PMU with clock gating technique is presented in three aspects, including system-level strategy, architecture-level map and implementation of the mechanism. The UDC with the PMU is implemented in a SMIC 0.13 mu m standard CMOS process. The results measured indicate that the supply current in the standby mode is reduced to about 0.26 mA while the current in the normal mode is about 51 mA. These findings suggest that the strategy exhibits better power efficiency.