EZ-USB® FX2LP™ CYStreamer Firmware Does Not Enumerate on a Custom Board - KBA86725

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Question: The CYStreamer firmware for EZ-USB® FX2LP™ (that comes with AN4053) works on the Cypress DVK (CY3684), but when it is downloaded onto a custom board, it does not enumerate. Why?



The CYStreamer firmware provided by Cypress to test the throughput capability of FX2LP is specifically designed for the CY3684 DVK. The DVK uses I/O expander ICs on the I2C lines to accommodate the seven-segment LED display.

In the CYStreamer firmware, this LED display is accessed using the EZUSB_WriteI2C() function. On custom boards, such a design may not exist, so the firmware freezes and enumeration fails.

The solution is to remove this functionality in the firmware. Just comment out these two lines in the code:

EZUSB_WriteI2C(LED_ADDR, 0x01, &(Digit[AlternateSetting])); EZUSB_WaitForEEPROMWrite(LED_ADDR);