Atmel Xplained Pro Evaluation Kit ATSAMD20-XPRO ATSAMD20-XPRO Scheda Tecnica

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ATSAMD20-XPRO
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Atmel | SMART SAM D20 [DATASHEET]
Atmel-42129K–SAM-D20_datasheet–06/2014
Fix/Workaround:
The BUFOVF flag must be manually cleared by software.
3 - The SERCOM SPI BUFOVF status bit is not set until the next character is received after a 
buffer overflow, instead of directly after the overflow has occurred. Furthermore the 
CTRLA.IBON bit will always be zero and cannot be changed. Errata reference: 10551
Fix/Workaround:
None.
35.3.10 ADC
1 - The automatic right shift of the result when accumulating/averaging ADC samples does 
not work. Errata reference: 10530
Fix/Workaround:
To accumulate or average more than 16 samples, one must add the number of automatic right 
shifts to AVGCTRL.ADJRES to perform the correct number of right shifts. For example, for 
averaging 128 samples, AVGCTRL.ADJRES must be written to 7 instead of 4, as the automatic 
right shift of 3 is not done. For oversampling to 16 bits resolution, AVGCTRL.ADJRES must be 
written to 4 instead of 0 as the automatic right shift of 4 is not done. 
The maximum number of right shifts that can be done using ADJRES is 7. This means that when 
averaging more than 128 samples, the result will be more than 12 bits, and the additional right 
shifts to get the result down to 12 bits must be done by firmware.
35.3.11 PTC
1 - Some gain settings for the PTC in self-capacitance mode do not work. The two lowest 
gain settings are not selectable and an attempt by the QTouch Library to set enable of these 
may result in a higher sensitivity than optimal for the sensor. The PTC will not detect all 
touches. This errata does not affect mutual-capacitance mode which operates as specified. 
Errata reference: 10684
Fix/Workaround:
Use SAM D20 revision C or later for self-capacitance touch sensing.
35.3.12 Flash
1 - When cache read mode is set to deterministic (READMODE=2), setting CACHEDIS=1 
does not lead to 0 wait states on Flash access. Errata reference: 10830
Fix/Workaround:
When disabling the cache (CTRLB.CACHEDIS=1), the user must also set READMODE to 0 
(CTRLB.READMODE=0).
2 - When NVMCTRL issues either erase or write commands and the NVMCTRL cache is not 
in LOW_POWER mode, CPU hardfault exception may occur. Errata reference: 10804
Fix/Workaround:
Either: