15.9 I/O Pin Characteristics

Note: The I/O pin characteristics numbers are for the micronontroller SAM L21.

There are three different pin types with three different speeds: Backup, Normal, and High Sink^(3,4).

The Drive Strength bit is located in the Pin Configuration register of the PORT (PORT.PINCFG.DRVSTR).

Table 15-11. I/O Pins Common Characteristics
Symbol	Parameter	Conditions	Min.	Typ.	Max.	Units
V_IL	Input low-level voltage	V_DD=1.8V-2.7V	-	-	0.25*V_DD	V
V_IL	Input low-level voltage	V_DD=2.7V-3.63V	-	-	0.3*V_DD
V_IH	Input high-level voltage	V_DD=1.8V-2.7V	0.7*V_DD	-	-
V_IH	Input high-level voltage	V_DD=2.7V-3.63V	0.55*V_DD	-	-
V_OL	Output low-level voltage	V_DD>1.8V, I_OL max	-	0.1*V_DD	0.2*V_DD
V_OH	Output high-level voltage	V_DD>1.8V, I_OH max	0.8*V_DD	0.9*V_DD	-
R_PULL	Pull-up - Pull-down resistance	All pins except PA24, PA25	20	40	60	kΩ
R_PULL	Pull-up - Pull-down resistance	PA24, PA25⁽¹⁾	50	100	150	kΩ
I_LEAK	Input leakage current	Pull-up resistors disabled	-1	+/-0.015	1	µA

Table 15-12. I/O Pins Maximum Output Current
Symbol	Parameter	Conditions	Backup Pins in Backup Mode⁽⁴⁾	Backup and Normal Pins⁽⁴⁾	High Sink Pins⁽³⁾	Backup and Normal Pins⁽⁴⁾	High Sink Pins⁽³⁾	Units
Symbol	Parameter	Conditions	Backup Pins in Backup Mode⁽⁴⁾	DRVSTR=0		DRVSTR=1
I_OL	Maximum Output low-level current	V_DD=1.8V-3V	0.005	1	2	2	4	mA
I_OL	Maximum Output low-level current	V_DD=3V-3.63V	0.008	2.5	6	6	12
I_OH	Maximum Output high-level current	V_DD=1.8V-3V	0.005	0.7	1.5	1.5	3
I_OH	Maximum Output high-level current	V_DD=3V-3.63V	0.008	2	5	5	10

Table 15-13. I/O Pins Dynamic Characteristics⁽¹⁾
Symbol	Parameter	Conditions	Backup Pins in Backup Mode⁽⁴⁾	Backup and Normal Pins⁽⁴⁾	High Sink Pins⁽³⁾	Backup and Normal Pins⁽⁴⁾	High Sink Pins⁽³⁾	Units
Symbol	Parameter	Conditions	Backup Pins in Backup Mode⁽⁴⁾	DRVSTR=0		DRVSTR=1		Units
t_RISE	Maximum Rise time	V_DD=3.3V, load=20pF	2000	13	6	6	4.5	ns
t_FALL	Maximum Fall time	V_DD=3.3V, load=20pF	2000	12	7	7	4.5	ns

The pins with I²C alternative mode available are compliant⁽²⁾ with I²C norms. All I²C pins support Standard mode (Sm), Fast mode (Fm), Fast plus mode (Fm+), and High speed mode (Hs, up to 3.4MHz). The available I²C pins are listed in the I/O Multiplexing section.

Note:

These values are based on simulation. They are not covered by production test limits or characterization.
The pins PA12, PA13, PB12, PB13, PB16, PB17, PB30, PB31 are limited on output low-level current in I²C Standard mode (Sm) and Fast mode (Fm). The limitation is 2.5mA instead of 3mA for V_OL=0.4V, and 3mA instead of 6mA for V_OL=0.6V.
The following pins are High Sink pins and have different properties than normal pins:
PA08, PA09, PA16, PA17, PA22, PA23, PA27, PA31.
The following pins are Backup pins and have different properties than normal pins:
PA00, PA01, PB00, PB01, PB02, PB03.