SPRUJB3 March 2024 AM67 , AM67A , TDA4AEN-Q1 , TDA4VEN-Q1
As the USB controllers are dual role controllers, capable of assuming a role of a host or device, the required pull-up/pull-down resistors cannot exist external to the device. These pull-up/pulldown resistors exist internal to the device, within the PHY to be more specific, and are enabled or disabled based on the role the controller assumes allowing for dynamic hardware configuration. When assuming the role of a host, the data lines are pulled low by the PHY enabling the internal 15KΩ resistors. When assuming the role of a device the required 1.5KΩ pull-up resistor on the D+ line is enabled automatically to signify the USB capability to the external host as a FS device (HS operation is negotiated during reset bus condition). Low-Speed Device functionality is not supported.