Data Sheet

1044
Atmel | SMART SAM D21 [DATASHEET]
Atmel-42181G–SAM-D21_Datasheet–09/2015
39.1.3.10 PTC
1 - WCOMP interrupt flag is not stable. The WCOMP interrupt flag will not
always be set as described in the datasheet. Errata reference: 12860
Fix/Workaround:
Do not use the WCOMP interrupt. Use the WCOMP event.
39.1.4 Revision D
39.1.4.1 Device
1 - In the table ""NVM User Row Mapping"", the WDT Window bitfield default
value on silicon is not as specified in the datasheet. The datasheet defines
the default value as 0x5, while it is 0xB on silicon. Errata reference: 13951
Fix/Workaround:
None.
2 - On pin PA24 and PA25 the pull-up and pull-down configuration is not
disabled automatically when alternative pin function is enabled. Errata
reference: 12368
Fix/Workaround:
For pin PA24 and PA25, the GPIO pull-up and pull-down must be disabled before
enabling alternative functions on them.
3 - If APB clock is stopped and GCLK clock is running, APB read access to
read-synchronized registers will freeze the system. The CPU and the DAP
AHB-AP are stalled, as a consequence debug operation is impossible.
Errata reference: 10416
Fix/Workaround:
Do not make read access to read-synchronized registers when APB clock is
stopped and GCLK is running. To recover from this situation, power cycle the
device or reset the device using the RESETN pin.
4 - In I2C Slave mode, writing the CTRLB register when in the AMATCH or
DRDY interrupt service routines can cause the state machine to reset. Errata
reference: 13574
Fix/Workaround:
Write CTRLB.ACKACT to 0 using the following sequence:
// If higher priority interrupts exist, then disable so that the
// following two writes are atomic.
SERCOM - STATUS.reg = 0;
SERCOM - CTRLB.reg = 0;
// Re-enable interrupts if applicable.
Write CTRLB.ACKACT to 1 using the following sequence: