If a simple design is the goal, USB2 port 0 can serve as a USB host. This allows combining host and device mode to be delivered through just one connector (typically a micro-A or -B connector). The USB2 interface is able to transmit data at 480Mbps. For higher speeds a USB3 is necessary.

 

Request for host mode is signaled through the ID pin on the USB connector and routed to the USB2_ID_PMIC signal on the module. To power devices in USB host mode, the OTG_EN signal enables +VBUS on the USB connector through a load switch with set 1 A current limit. The +VBUS source can be a dedicated boost regulator fed by +VSYS, or if +VSYS has a minimum of 4.75 V, +VSYS can be used as a +VBUS source. It is good design practice to add an ESD protection diode, a PTC fuse, and EMI filtering to +VBUS, and to add common-mode chokes with built-in ESD diodes to USB data signals.

 

Signal

Module Connector.Pin

Pin Direction

Use

USB2_1_DN

J7.63

Bidirectional

USB 2.0 port 1 data negative

USB2_1_DP

J7.65

Bidirectional

USB 2.0 port 1 data positive

Para obtener información más completa sobre las optimizaciones del compilador, consulte nuestro Aviso de optimización.