Refer to the Application Notes USB Peripheral Basics - AN57294 at http://www.cypress.com/?rID=39327.
You need to configure your PSoC as a bulk device that transmits data to the host(PC) continuously. The DMA has to be
configured to have ADC as source and a memory buffer as destination.
Refer to this Application Note to learn about DMA Using DMA on PSoC® 3 / PSoC 5 - AN52705