Table 48-3. Reset Circuit Connections
Signal Name
Recommended Pin Connection
Description
RESET
Reset low level threshold voltage
V
DDIO
= 1.6V - 2.0V: Below 0.33 * V
DDIO
V
DDIO
= 2.7V - 3.6V: Below 0.36 * V
DDIO
Decoupling/filter capacitor 100nF
Pull-up resistor 10kΩ
Resistor in series with the switch 330Ω
Reset pin
1. These values are only given as a typical example.
2. The SAM L22 features an internal pull-up resistor on the RESET pin, hence an external pull-up is
optional.
48.5. Unused or Unconnected Pins
For unused pins the default state of the pins will give the lowest current leakage. Thus there is no need to
do any configuration of the unused pins in order to lower the power consumption.
48.6. Clocks and Crystal Oscillators
The SAM L22 can be run from internal or external clock sources, or a mix of internal and external
sources. An example of usage can be to use the internal 16MHz oscillator as source for the system clock
and an external 32.768kHz watch crystal as clock source for the Real-Time counter (RTC).
48.6.1. External Clock Source
Figure 48-7. External Clock Source Schematic
XOUT/GPIO
XIN
NC/GPIO
External
Clock
Table 48-4. External Clock Source Connections
Signal Name
Recommended Pin Connection
Description
XIN
XIN is used as input for an external clock signal
Input for inverting oscillator pin
XOUT/GPIO
Can be left unconnected or used as normal GPIO
NC/GPIO
Atmel SAM L22G / L22J / L22N [DATASHEET]
Atmel-42402E-SAM L22G / L22J / L22N_Datasheet_Complete-07/2016
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