The Q&A is applicable for Cypress FX3 also.
>>Is there any Phy register that can fine-tune the USB signal strengths ? If yes please let me know the register details ?
The Registers PCS_TX_SWING_FULL and PCS_TX_SWING_LOW are used for setting the TX Amplitude in Full Swing and Low Swing Mode. For adjusting these registers, we have the API CyU3PUsbSetTxSwing. This API makes use of a parameter "swing". This can be used to adjust the registers. Please make sure that this API is called before CyU3PConnectState is called. For more details, please refer to Page 535 of FX3 API Guide.
The Registers PCS_TX_DEEMPH_3P5DB and PCS_TX_DEEMPH_6DB are used for setting TX de-emphasis at 3.5dB and 6dB. For changing these registers, we have the API CyU3PUsbSetTxDeemphasis. Please go through Page 535 of FX3 API guide to know the limits within which these registers can be adjusted. Also make sure that this API is called before CyU3PConnectState is called.
Thanks for your inputs.