I used to write an ad for EZUSB (2131) series chip DLL. Examples are

usb通信检测软件，很实用，重要-usb detection communications software, very useful, important

高性能USB转串口（可高达10Mbps）完整的源代码-High-performance USB to Serial (up to 10Mbps) complete source code

D12的驱动程序-D12 driver

利用Visual c++实现USB接口的枚举,初始化,以及数据的传输-Visual c achieve USB enumeration, initialization, and data transmission

some examples of AD DA convertion by EZUSB

USB Mass Storage Designing and Programming Devices and Embedded Hosts

High volume USB 2.0 devices will be designed using ASIC technology with embedded USB 2.0 support. For full-speed USB devices the operating frequency was low enough to allow data recovery to be handled in a vendors VHDL code, with the ASIC vendor providing only a simple level translator to meet the USB signaling requirements. Today s gate arrays operate comfortably between 30 and 60 MHz. With USB 2.0 signaling running at hundreds of MHz, the existing design methodology must change.

RS232-USB转化器将老式RS2332串口转换成USB接口来与PC机进行数据传输，USB控制器采用CY7C63001A-RS232-USB converter old RS2332 will be converted into a USB serial interface with the PC for data transfer, USB controller CY7C63001A

VC编写的一个USB通用程序-VC prepared by a USB common procedures

很实用的通用usb驱动程序的应用程序开发指南-Very practical generic usb driver Application Development Guide