Data Sheet

1023
Atmel | SMART SAM D21 [DATASHEET]
Atmel-42181G–SAM-D21_Datasheet–09/2015
- Use PA24 and PA25 for peripherals or only as output pins.
- Or configure PA31 to PA24 for on-demand sampling (CTRL[31:24] all zeroes)
and access the IN register through the APB (not the IOBUS), to allow waiting for
on-demand sampling.
6 - SYSTICK calibration value is wrong. Errata reference: 14154
Fix/Workaround:
right SYSTICK calibration value is 0x40000000.
7 - In Standby, Idle1 and Idle2 sleep modes the device might not wake up
from sleep. An External Reset, Power on Reset or Watch Dog Reset will start
the device again. Errata reference: 13140
Fix/Workaround:
the SLEEPPRM bits in the NVMCTRL.CTRLB register must be written to 3
(NVMCTRL - CTRLB.bit.SLEEPPRM = 3) to ensure correct operation of the
device. The average power consumption of the device will increase with 20uA
compared to numbers in the electrical characteristics chapter.
8 - While the internal startup is not completed, PA07 pin is driven low by the
chip. Then as all the other pins it is configured as an High Impedance pin.
Errata reference: 12118
Fix/Workaround:
None
9 - Digital pin outputs from Timer/Counters, AC (Analog Comparator), GCLK
(Generic Clock Controller), and SERCOM (I2C and SPI) do not change value
during standby sleep mode. Errata reference: 12537
Fix/Workaround:
Set the voltage regulator in Normal mode before entering STANDBY sleep mode
in order to keep digital pin output enabled. This is done by setting the RUNSTDBY
bit in the VREG register.
10 - The I2S is non-functional. Errata reference: 12275
Fix/Workaround:
None
11 - The voltage regulator in low power mode is not functional at
temperatures above 85C. Errata reference: 12291
Fix/Workaround:
Enable normal mode on the voltage regulator in standby sleep mode.
Example code:
// Set the voltage regulator in normal mode configuration in standby sleep mode
SYSCTRL->VREG.bit.RUNSTDBY = 1;