User`s manual

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6.9. USB
The USB module can be configured as Host, Device or OTG with the correct switch settings on SW6.
Function / Device / Slave mode: This mode does not take any external power circuitry to implement. Simply put the
SW6 DIP switches to the proper setting as in table 6-7 and configure the software appropriately.
Host mode: Connect the included MiniAB to Host adapter Cable to have the proper cable connection for USB Host.
This mode uses U12 and associated passive circuitry to create USB Power. Set SW6 DIP switches to the settings
shown in table 6-7. Note that you will have to add an external 5V regulated supply that sources 1 Amp or greater to J4 in
order to meet the USB Specification for power delivery (500ma).
OTG: Set SW6 DIP switches to the settings shown in table 6-7. Note that the Maxim MAX3353EEUE and associated
circuitry will create the proper USB OTG voltages. Note the Maxim IC must be configured in software using the I2C bus
(Address 0x58) for proper operation. Note that you will have to add an external 5V regulated supply that sources more
than 1 Amp to J4 in order to meet the USB Specification for power delivery (500ma).
Table 6-6 contains details of the USB signal descriptions and pin connections. Table 6-7 details how to set the SW6 DKP
switches for each USB mode.
Description Function Microcontroller
Pin Number
USB_VBUS USB cable connection monitor pin 30
USD+ USB data I/O pin 37
USD- USB data I/O pin 36
VCC_USB Power supply pin for USB built-in transceiver 35
VSS_USB Ground pin for USB built-in transceiver 38
USB_DPUPEA Pull-up control pin A 25
USB _ID OTG USB ID 28
USB_OVRCURA_DPUPEB Host / OTG Over-current detect / Function Pull-up control pin B 32
USB_DRPD D- Pull Down 26
USB_DPRPD D+ Pull Down 23
USB0_EXICEN Expansion 27
Table 6-6: USB Pin Definitions
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