Datasheet: 
CY7C64713.pdf
CY7C64713-100AXC
EZ-USB FX1 USB Microcontroller; Full Speed USB Peripheral Controller
Series:CY7C; Memory Size, RAM:16KB; No of I/O Lines:40; No. of Timers:3; Clock Frequency:24MHz; Interface Type:I2C, USART, USB; Voltage, Supply Min:3.15V; Voltage, Supply Max:3.45V;
Version: *F
EZ-USB FX1™ USB Microcontroller Full Speed USB Peripheral Controller
Features
- Single Chip Integrated USB Transceiver, SIE, and Enhanced 8051 Microprocessor
- Fit, Form, and Function Upgradable to the FX2LP (CY7C68013A)
- Pin compatible
- Object code compatible
- Functionally compatible (FX1 functionality is a Subset of the FX2LP)
- Draws No More than 65 mA in Any Mode, Making the FX1 Suitable for Bus Powered Applications
- Software: 8051 Runs from Internal RAM, which is:
- Downloaded using USB
- Loaded from EEPROM
- For more, see pdf
Functional Description
EZ-USB FX1™ (CY7C64713) is a full speed, highly integrated, USB microcontroller. By integrating the USB transceiver, Serial Interface Engine (SIE), enhanced 8051 microcontroller, and a programmable peripheral interface in a single chip, Cypress has created a very cost effective solution that provides superior time-to-market advantages.
The EZ-USB FX1 is more economical, because it incorporates the USB transceiver and provides a smaller footprint solution than the USB SIE or external transceiver implementations. With EZ-USB FX1, the Cypress Smart SIE handles most of the USB protocol in hardware, freeing the embedded microcontroller for application specific functions and decreasing the development time to ensure USB compatibility.
Product link: 
http://www.cypress.com/?rID=14172