Data Sheet

1021
Atmel | SMART SAM D21 [DATASHEET]
Atmel-42181G–SAM-D21_Datasheet–09/2015
39. Errata
39.1 Device Variant A
39.1.1 Revision A
1 - TCC0/WO[6] on PA16 and TCC0/WO[7] on PA17 are not available. Errata
reference: 11622
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:
// If higher priority interrupts exist, then disable so that the
// following two writes are atomic.
SERCOM - STATUS.reg = 0;
SERCOM - CTRLB.reg = SERCOM_I2CS_CTRLB_ACKACT;