The 'GPIO57_I2S-MCLK_VIO3_SW' signal is connected to the I2S-MCLK pin of the CYUSB3014 device in the CYUSB3KIT-003 Superspeed Explorer kit. The signal is routed to the rectangular expansion header.
Please tell me the function of this signal.
This GPIO can be used as an I2S_MCLK if you connect a I2S receiver device to the SuperSpeed Explorer Kit. If you are not using the I2S interface, you can use it as a normal GPIO too.