AT32UC3C0512C Datasheet, PDF (24/110 Pages) ATMEL Corporation – High Performance, Low Power 32-bit AVR Microcontroller

AT32UC3C
Table 3-7. Signal Description List
Signal Name
DP
VBUS
ID
VBOF
Function
USB Device Port Data +
USB VBUS Monitor and OTG Negociation
ID Pin of the USB Bus
USB VBUS On/off: bus power control port
Type
Analog
Analog
Input
Input
output
Active
Level Comments
3.4 I/O Line Considerations
3.4.1
JTAG pins
The JTAG is enabled if TCK is low while the RESET_N pin is released. The TCK, TMS, and TDI
pins have pull-up resistors when JTAG is enabled. The TCK pin always have pull-up enabled
during reset. The TDO pin is an output, driven at VDDIO1, and has no pull-up resistor. The
JTAG pins can be used as GPIO pins and muxed with peripherals when the JTAG is disabled.
Please refer to Section 3.2.4 for the JTAG port connections.
3.4.2
RESET_N pin
The RESET_N pin integrates a pull-up resistor to VDDIO1. As the product integrates a power-on
reset cell, the RESET_N pin can be left unconnected in case no reset from the system needs to
be applied to the product.
The RESET_N pin is also used for the aWire debug protocol. When the pin is used for debug-
ging, it must not be driven by external circuitry.
3.4.3 TWI pins
When these pins are used for TWI, the pins are open-drain outputs with slew-rate limitation and
inputs with inputs with spike-filtering. When used as GPIO-pins or used for other peripherals, the
pins have the same characteristics as GPIO pins.
3.4.4
GPIO pins
All I/O lines integrate programmable pull-up and pull-down resistors. Most I/O lines integrate
drive strength control, see Table 3-1. Programming of this pull-up and pull-down resistor or this
drive strength is performed independently for each I/O line through the GPIO Controllers.
After reset, I/O lines default as inputs with pull-up/pull-down resistors disabled. After reset, out-
put drive strength is configured to the lowest value to reduce global EMI of the device.
When the I/O line is configured as analog function (ADC I/O, AC inputs, DAC I/O), the pull-up
and pull-down resistors are automatically disabled.
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