SAM4L Datasheet, PDF (30/1185 Pages) ATMEL Corporation – ATSAM ARM-based Flash MCU

ATSAM4L4/L2
3.3.3
3.3.4
3.3.5
3.3.6
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.
GPIO Pins
All the I/O lines integrate a pull-up/pull-down resistor and slew rate controller. Programming
these features is performed independently for each I/O line through the GPIO Controllers. After
reset, I/O lines default as inputs with pull-up and pull-down resistors disabled and slew rate
enabled.
High-drive Pins
The six pins PA02, PB00, PB01, PC04, PC05 and PC06 have high-drive output capabilities.
Refer to Section 42.5.2 ”High-drive I/O Pin : PA02, PC04, PC05, PC06” on page 1119 for electri-
cal characteristics.
USB Pins
When these pins are used for USB, the pins are behaving according to the USB specification.
When used as GPIO pins or used for other peripherals, the pins have the same behavior as
other normal I/O pins, but the characteristics are different. Refer to Section 42.5.3 ”USB I/O Pin :
PA25, PA26” on page 1120 for electrical characteristics.
To be able to use the USB I/O the VDDIN power supply must be 3.3V nominal.
3.3.7
ADC Input Pins
These pins are regular I/O pins powered from the VDDANA.
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