Atmel Xplained Evaluation Board AT32UC3A3-XPLD AT32UC3A3-XPLD Datenbogen
Produktcode
AT32UC3A3-XPLD
629
32072H–AVR32–10/2012
AT32UC3A3
27.6
Product Dependencies
In order to use this module, other parts of the system must be configured correctly, as described
below.
below.
27.6.1
I/O Lines
The USB_VBOF and USB_ID pins are multiplexed with I/O Controller lines and may also be
multiplexed with lines of other peripherals. In order to use them with the USB, the user must first
configure the I/O Controller to assign them to their USB peripheral functions.
multiplexed with lines of other peripherals. In order to use them with the USB, the user must first
configure the I/O Controller to assign them to their USB peripheral functions.
If USB_ID is used, the I/O Controller must be configured to enable the internal pull-up resistor of
its pin.
its pin.
If USB_VBOF or USB_ID is not used by the application, the corresponding pin can be used for
other purposes by the I/O Controller or by other peripherals.
other purposes by the I/O Controller or by other peripherals.
27.6.2
Clocks
The clock for the USBB bus interface (CLK_USBB) is generated by the Power Manager. This
clock is enabled at reset, and can be disabled in the Power Manager. It is recommended to dis-
able the USBB before disabling the clock, to avoid freezing the USBB in an undefined state.
clock is enabled at reset, and can be disabled in the Power Manager. It is recommended to dis-
able the USBB before disabling the clock, to avoid freezing the USBB in an undefined state.
The UTMI transceiver needs a 12 MHz clock as a clock reference for its internal 480 MHz PLL.
Before using the USB, the user must ensure that this 12 MHz clock is available. The 12 MHz
input is connected to a Generic Clock (GCLK_USBB) provided by the Power Manager.
Before using the USB, the user must ensure that this 12 MHz clock is available. The 12 MHz
input is connected to a Generic Clock (GCLK_USBB) provided by the Power Manager.
27.6.3
Interrupts
The USBB interrupt request line is connected to the interrupt controller. Using the USBB inter-
rupt requires the interrupt controller to be programmed first.
rupt requires the interrupt controller to be programmed first.