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

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Atmel | SMART SAM D20 [DATASHEET]

Atmel-42129K–SAM-D20_datasheet–06/2014

17.8.8 Clear

Name: CLEAR

Offset: Offset: 0x8

Reset: 0x00

Property: Write-Protected, Write-Synchronized

z Bits 7:0 – CLEAR: Watchdog Clear

Writing 0xA5 to this register will clear the Watchdog Timer and the watchdog time-out period is restarted. Writing

any other value will issue an immediate system reset.

Bit76543210

CLEAR[7:0]

AccessWWWWWWWW

Reset00000000