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
31
8493A–AVR–02/12
XMEGA C4
14.4 Input sensing
Input sensing is synchronous or asynchronous depending on the enabled clock for the ports,
and the configuration is shown in Figure 14-7.
Figure 14-7. Input sensing system overview.
When a pin is configured with inverted I/O, the pin value is inverted before the input sensing.
14.5 Alternate Port Functions
Most port pins have alternate pin functions in addition to being a general purpose I/O pin. When
an alternate function is enabled, it might override the normal port pin function or pin value. This
happens when other peripherals that require pins are enabled or configured to use pins. If and
how a peripheral will override and use pins is described in the section for that peripheral. ”Pinout
and Pin Functions” on page 52 shows which modules on peripherals that enable alternate func-
tions on a pin, and which alternate functions that are available on a pin.
INVERTED I/O
Interrupt
Control
IREQ
Event
Pn
D
Q
R
D
Q
R
Synchronizer
INn
EDGE
DETECT
Asynchronous sensing
Synchronous sensing
EDGE
DETECT