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AN76348 - Differences in Implementation of EZ-USB® FX2LP and EZ-USB FX3 Applications | Cypress Semiconductor

AN76348 - Differences in Implementation of EZ-USB® FX2LP and EZ-USB FX3 Applications

Last Updated: 
May 28, 2020
AN76348 describes the differences between the implementation of applications based on EZ-USB FX2LP¿ and EZ-USB FX3.

With the release of the USB 3.0 specification, USB controller chips required rearchitecting to handle the ten-fold increase in USB bandwidth over the USB 2.0 specification. Cypress offers USB controllers for applications based on USB 2.0 (EZ-USB® FX2LP™) and USB 3.0 (EZ-USB FX3™).This application note describes the implementation differences between the two controllers. Example applications highlight those differences at the architectural, hardware, and firmware framework levels. While this application note emphasizes the new FX3 features, it provides links to FX2LP background materials. For the complete list of SuperSpeed code examples, visit and for the complete list of Hi-Speed code examples, visit


Cypress EZ-USB FX3 is a USB 3.0 peripheral controller with highly integrated and flexible features that add USB 3.0 functionality to any system.

FX3 has a fully configurable, parallel general programmable interface called GPIF II, which can connect to an external processor, ASIC, or FPGA. The GPIF II is an enhanced version of the GPIF in FX2LP, Cypress’s flagship USB 2.0 product. GPIF II provides glueless connectivity to popular interfaces such as asynchronous SRAM, asynchronous and synchronous address data multiplexed interface, and others. To accommodate the USB 3.0 SuperSpeed signaling rates, FX3 offers architectural enhancements over FX2LP such as a RISC processor and DMA system. This application note explains the architectural differences and introduces the FX3 RTOS-based firmware frameworks.