Datasheet
Table Of Contents
- Features
- 1. Ordering Information
- 2. Pinout/Block Diagram
- 3. Overview
- 4. Resources
- 5. Capacitive touch sensing
- 6. AVR CPU
- 7. Memories
- 8. Event System
- 9. System Clock and Clock options
- 9.1 Features
- 9.2 Overview
- 9.3 Clock Sources
- 9.3.1 32kHz Ultra Low Power Internal Oscillator
- 9.3.2 32.768kHz Calibrated Internal Oscillator
- 9.3.3 32.768kHz Crystal Oscillator
- 9.3.4 0.4 - 16MHz Crystal Oscillator
- 9.3.5 2MHz Run-time Calibrated Internal Oscillator
- 9.3.6 32MHz Run-time Calibrated Internal Oscillator
- 9.3.7 External Clock Sources
- 9.3.8 PLL with 1x-31x Multiplication Factor
- 10. Power Management and Sleep Modes
- 11. System Control and Reset
- 12. WDT – Watchdog Timer
- 13. Interrupts and Programmable Multilevel Interrupt Controller
- 14. I/O Ports
- 15. TC0/1 – 16-bit Timer/Counter Type 0 and 1
- 16. TC2 – Timer/Counter Type 2
- 17. AWeX – Advanced Waveform Extension
- 18. Hi-Res – High Resolution Extension
- 19. RTC – 16-bit Real-Time Counter
- 20. USB – Universal Serial Bus Interface
- 21. TWI – Two-Wire Interface
- 22. SPI – Serial Peripheral Interface
- 23. USART
- 24. IRCOM – IR Communication Module
- 25. CRC – Cyclic Redundancy Check Generator
- 26. ADC – 12-bit Analog to Digital Converter
- 27. AC – Analog Comparator
- 28. Programming and Debugging
- 29. Pinout and Pin Functions
- 30. Peripheral Module Address Map
- 31. Instruction Set Summary
- 32. Packaging information
- 33. Electrical Characteristics TBD
- 34. Typical Characteristics TBD
- 35. Errata
- 36. Datasheet Revision History
- Table of Contents
12
8493A–AVR–02/12
XMEGA C4
7.3 Flash Program Memory
The Atmel AVR XMEGA devices contain on-chip, in-system reprogrammable flash memory for
program storage. The flash memory can be accessed for read and write from an external pro-
grammer through the PDI or from application software running in the device.
All AVR CPU instructions are 16 or 32 bits wide, and each flash location is 16 bits wide. The
flash memory is organized in two main sections, the application section and the boot loader sec-
tion. The sizes of the different sections are fixed, but device-dependent. These two sections
have separate lock bits, and can have different levels of protection. The store program memory
(SPM) instruction, which is used to write to the flash from the application software, will only oper-
ate when executed from the boot loader section.
The application section contains an application table section with separate lock settings. This
enables safe storage of nonvolatile data in the program memory.
7.3.1 Application Section
The Application section is the section of the flash that is used for storing the executable applica-
tion code. The protection level for the application section can be selected by the boot lock bits
for this section. The application section can not store any boot loader code since the SPM
instruction cannot be executed from the application section.
7.3.2 Application Table Section
The application table section is a part of the application section of the flash memory that can be
used for storing data. The size is identical to the boot loader section. The protection level for the
application table section can be selected by the boot lock bits for this section. The possibilities
for different protection levels on the application section and the application table section enable
safe parameter storage in the program memory. If this section is not used for data, application
code can reside here.
7.3.3 Boot Loader Section
While the application section is used for storing the application code, the boot loader software
must be located in the boot loader section because the SPM instruction can only initiate pro-
gramming when executing from this section. The SPM instruction can access the entire flash,
including the boot loader section itself. The protection level for the boot loader section can be
selected by the boot loader lock bits. If this section is not used for boot loader software, applica-
tion code can be stored here.
Figure 7-1. Flash program memory (Hexadecimal address).
Word Address
Application Section
(128K/16K)
...
/ 37FF / 17FF
/ 3800 / 1800
Application Table Section
(4K/4K)
/3FFF/1FFF
/ 4000 / 2000
Boot Section
(4K/4K)
/ 47FF / 27FF