Datasheet

ManualsBrandsMICROCHIP TECHNOLOGY ManualsDev KitsPCB design board

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Table Of Contents

Description
Features
1. Configuration Summary
2. Ordering Information
- 2.1 SAM D20E
- 2.2 SAM D20G
- 2.3 SAM D20J
3. Block Diagram
4. Pinout
- 4.1 SAM D20J
- 4.2 SAM D20G
- 4.3 SAM D20E
5. I/O Multiplexing and Considerations
- 5.1 Multiplexed Signals
- 5.2 Other Functions
  - 5.2.1 Oscillator Pinout
  - 5.2.2 Serial Wire Debug Interface Pinout
6. Signal Descriptions List
7. Power Supply and Start-Up Considerations
- 7.1 Power Domain Overview
- 7.2 Power Supply Considerations
- 7.3 Power-Up
- 7.4 Power-On Reset and Brown-Out Detector
8. Product Mapping
9. Memories
- 9.1 Embedded Memories
- 9.2 Physical Memory Map
- 9.3 Non-Volatile Memory (NVM) User Row Mapping
- 9.4 NVM Software Calibration Area Mapping
- 9.5 Serial Number
10. Processor and Architecture
- 10.1 Cortex-M0+ Processor
- 10.2 Nested Vector Interrupt Controller
  - 10.2.1 Overview
  - 10.2.2 Interrupt Line Mapping
- 10.3 High-Speed Bus Matrix
  - 10.3.1 Features
  - 10.3.2 Configuration
- 10.4 AHB-APB Bridge
- 10.5 PAC – Peripheral Access Controller
  - 10.5.1 Overview
- 10.6 Register Description
11. Peripherals Configuration Overview
12. DSU – Device Service Unit
- 12.1 Overview
- 12.2 Features
- 12.3 Block Diagram
- 12.4 Signal Description
- 12.5 Product Dependencies
- 12.6 Debug Operation
- 12.7 Chip-Erase
- 12.8 Programming
- 12.9 Intellectual Property Protection
- 12.10 Device Identification
  - 12.10.1 CoreSight Identification
  - 12.10.2 DSU Chip Identification Method:
- 12.11 Functional Description
- 12.12 Register Summary
- 12.13 Register Description
13. Clock System
- 13.1 Clock Distribution
- 13.2 Synchronous and Asynchronous Clocks
- 13.3 Register Synchronization
- 13.4 Enabling a Peripheral
- 13.5 On-demand, Clock Requests
- 13.6 Power Consumption vs Speed
- 13.7 Clocks after Reset
14. GCLK – Generic Clock Controller
- 14.1 Overview
- 14.2 Features
- 14.3 Block Diagram
- 14.4 Signal Description
- 14.5 Product Dependencies
- 14.6 Functional Description
- 14.7 Register Summary
- 14.8 Register Description
15. PM – Power Manager
- 15.1 Overview
- 15.2 Features
- 15.3 Block Diagram
- 15.4 Signal Description
- 15.5 Product Dependencies
- 15.6 Functional Description
- 15.7 Register Summary
- 15.8 Register Description
16. SYSCTRL – System Controller
- 16.1 Overview
- 16.2 Features
- 16.3 Block Diagram
- 16.4 Signal Description
- 16.5 Product Dependencies
- 16.6 Functional Description
- 16.7 Register Summary
- 16.8 Register Description
17. WDT – Watchdog Timer
- 17.1 Overview
- 17.2 Features
- 17.3 Block Diagram
- 17.4 Signal Description
- 17.5 Product Dependencies
- 17.6 Functional Description
- 17.7 Register Summary
- 17.8 Register Description
18. RTC – Real-Time Counter
- 18.1 Overview
- 18.2 Features
- 18.3 Block Diagram
- 18.4 Signal Description
- 18.5 Product Dependencies
- 18.6 Functional Description
- 18.7 Register Summary
- 18.8 Register Description
19. EIC – External Interrupt Controller
- 19.1 Overview
- 19.2 Features
- 19.3 Block Diagram
- 19.4 Signal Description
- 19.5 Product Dependencies
- 19.6 Functional Description
- 19.7 Register Summary
- 19.8 Register Description
20. NVMCTRL – Non-Volatile Memory Controller
- 20.1 Overview
- 20.2 Features
- 20.3 Block Diagram
- 20.4 Signal Description
- 20.5 Product Dependencies
- 20.6 Functional Description
- 20.7 Register Summary
- 20.8 Register Description
21. PORT
- 21.1 Overview
- 21.2 Features
- 21.3 Block Diagram
- 21.4 Signal Description
- 21.5 Product Dependencies
- 21.6 Functional Description
- 21.7 Register Summary
- 21.8 Register Description
22. EVSYS – Event System
- 22.1 Overview
- 22.2 Features
- 22.3 Block Diagram
- 22.4 Signal Description
- 22.5 Product Dependencies
- 22.6 Functional Description
- 22.7 Register Summary
- 22.8 Register Description
23. SERCOM – Serial Communication Interface
- 23.1 Overview
- 23.2 Features
- 23.3 Block Diagram
- 23.4 Signal Description
- 23.5 Product Dependencies
- 23.6 Functional Description
24. SERCOM USART – SERCOM Universal Synchronous and Asynchronous Receiver and Transmitter
- 24.1 Overview
- 24.2 Features
- 24.3 Block Diagram
- 24.4 Signal Description
- 24.5 Product Dependencies
- 24.6 Functional Description
- 24.7 Register Summary
- 24.8 Register Description
25. SERCOM SPI – SERCOM Serial Peripheral Interface
- 25.1 Overview
- 25.2 Features
- 25.3 Block Diagram
- 25.4 Signal Description
- 25.5 Product Dependencies
- 25.6 Functional Description
- 25.7 Register Summary
- 25.8 Register Description
26. SERCOM I2C – SERCOM Inter-Integrated Circuit
- 26.1 Overview
- 26.2 Features
- 26.3 Block Diagram
- 26.4 Signal Description
- 26.5 Product Dependencies
- 26.6 Functional Description
- 26.7 Register Summary
- 26.8 Register Description
  - 26.8.1 I2C Slave Register Description
  - 26.8.2 I2C Master Register Description
27. TC – Timer/Counter
- 27.1 Overview
- 27.2 Features
- 27.3 Block Diagram
- 27.4 Signal Description
- 27.5 Product Dependencies
- 27.6 Functional Description
- 27.7 Register Summary
- 27.8 Register Description
28. ADC – Analog-to-Digital Converter
- 28.1 Overview
- 28.2 Features
- 28.3 Block Diagram
- 28.4 Signal Description
- 28.5 Product Dependencies
- 28.6 Functional Description
- 28.7 Register Summary
- 28.8 Register Description
29. AC – Analog Comparators
- 29.1 Overview
- 29.2 Features
- 29.3 Block Diagram
- 29.4 Signal Description
- 29.5 Product Dependencies
- 29.6 Functional Description
- 29.7 Additional Features
- 29.8 Register Summary
- 29.9 Register Description
30. DAC – Digital-to-Analog Converter
- 30.1 Overview
- 30.2 Features
- 30.3 Block Diagram
- 30.4 Signal Description
- 30.5 Product Dependencies
- 30.6 Functional Description
- 30.7 Register Summary
- 30.8 Register Description
31. PTC - Peripheral Touch Controller
- 31.1 Overview
- 31.2 Features
- 31.3 Block Diagram
- 31.4 Signal Description
- 31.5 Product Dependencies
  - 31.5.1 I/O Lines
  - 31.5.2 Clocks
- 31.6 Functional Description
32. Electrical Characteristics
- 32.1 Disclaimer
- 32.2 Absolute Maximum Ratings
- 32.3 General Operating Ratings
- 32.4 Supply Characteristics
- 32.5 Maximum Clock Frequencies
- 32.6 Power Consumption
- 32.7 I/O Pin Characteristics
- 32.8 Analog Characteristics
- 32.9 NVM Characteristics
- 32.10 Oscillators Characteristics
- 32.11 PTC Typical Characteristics
- 32.12 Timing Characteristics
33. Packaging Information
- 33.1 Thermal Considerations
  - 33.1.1 Thermal Resistance Data
  - 33.1.2 Junction Temperature
- 33.2 Package Drawings
- 33.3 Soldering Profile
34. Schematic Checklist
- 34.1 Introduction
- 34.2 Power Supply
  - 34.2.1 Power Supply Connections
- 34.3 External Analog Reference Connections
- 34.4 External Reset Circuit
- 34.5 Unused or Unconnected Pins
- 34.6 Clocks and Crystal Oscillators
- 34.7 Programming and Debug Ports
35. Errata
- 35.1 Revision D
- 35.2 Revision C
- 35.3 Revision B
- 35.4 Revision A
36. Datasheet Revision History
- 36.1 Rev. K – 05/2014
- 36.2 Rev. J – 12/2013
- 36.3 Rev. I – 12/2013
- 36.4 Rev. H – 10/2013
- 36.5 Rev. G – 10/2013
- 36.6 Rev. F – 10/2013
- 36.7 Rev. E – 09/2013
- 36.8 Rev. D – 08/2013
- 36.9 Rev. C – 07/2013
- 36.10 Rev. B – 07/2013
- 36.11 Rev. A – 06/2013
Appendix A. Conventions
- A.1 Numerical Notation
- A.2 Memory Size and Type
- A.3 Frequency and Time
- A.4 Registers and Bits
Appendix B. Acronyms and Abbreviations
Table of Contents

632

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: