The evolving complexity of the newer Universal Serial Bus (USB) devices has necessitated the need for low cost USB 2.0 Host solution. This paper addresses the key reasons to have integrated hub and Enhanced Host controller interface (EHCI) in the newer generation of embedded hosts. Also, this paper will provide design guidelines for such integrated solutions, and the factors to be considered for such designs. The figure depicts the host controller solution from Arasan, which integrates Arasan’s Enhanced Host Controller Interface and USB 2.0 Hub IPs. The Enhanced Host Controller Interface module is responsible for the high speed traffic, while the USB 2.0 Hub is responsible for the high speed, full speed, and low speed traffic, thus eliminating the necessity to have a companion host controller. This is an attractive feature for embedded systems, since this eliminates the software driver requirement for the companion host controller, which saves memory space required for the driver. This architecture also paves way for compound devices to be implemented within the system. Read the rest of the paper here
Integrated EHCI and USB 2.0 Hub for Embedded Hosts