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ATtiny817 Product Family

A New Level of System Performance with Core Independent Peripherals

The ATtiny817 product series features a high level of Core Independent Peripherals (CIPs) that can be combined to perform a wide variety of functions without the core. Combined with the Event System, this brings a whole new level of system performance allowing peripherals to communicate, transfer data and signal directly to each other to make intelligent decisions without the use of the CPU. This increases throughput, lowers power consumption and improves predictability with capacitive touch (PTC), analog and serial peripherals. The Event System offers a huge benefit for many applications such as white goods, automotive, lighting and more.

Event System

The Event Systems allows peripherals to communicate directly with each other without involving the CPU or bus resources. The Event System is network independent of the traditional data bus paths. Meaning, different triggers at the peripheral level can result in an event, such as a timer tick triggering a reaction in another peripheral. The Event System has six independent channels and offers a fixed latency of two cycles. In addition, since there is no jitter, it is 100% deterministic method and a perfect fit for real-time applications. No events are lost, and they are handled at a peripheral level in two cycles, even if the CPU is performing a non-maskable interrupt.

Capacitive Touch

The Peripheral Touch Controller (PTC) is an autonomous unit that acquires and processes capacitive touch signals. It supports buttons, sliders and wheel configurations in addition to proximity sensing with one pin per sensor and no external components needed. This CIP offers a broad range of touch enabled features, such as mutual and self-capacitance, noise filtering, moisture tolerance, auto calibration over temperature and voltage, as well as wake-up upon touch and/or proximity from sleep mode. All of this enables a user-friendly interface that improves system performance and offers increased robustness, lower power consumption and end-application differentiation.

Integrated Analog

The on board dual 10-bit, 150 ksps ADC and 8-bit DAC with multiple selectable internal voltage references and comparators can be connected internally to create closed-loop feedback without requiring pins or PCB space or can be used for other functions within the applications. In addition the on-board analog comparator offers fast propagation delay which is configurable through hysteresis. The analog comparator can also be connected directly with the DAC and the output is directly available on a pin.

On-board Safety and Monitoring

The ATtiny817 product family features the Windowed Watchdog timer and Cyclic Redundancy Check with Automated Memory Scan. Together, these hardware-based CIPs provide engineers with the necessary features to easily incorporate safety and system management into their application.

Flexible and Feature-Rich Timer/Counters

The ATtiny817 series of devices feature two 16-bit timer/counters and one 12-bit timer/counter optimized for control applications. The 16-bit counters can be split into 8-bit counters and proved accurate program execution timing, frequency and waveform generation, and command execution. Two timer/counters also support input capture with time and frequency measurement of digital signals. The 12-bit timer/counter is a high-performance waveform controller that consists of an asynchronous counter, a prescaler, compare logic, capture logic, and control logic. This is perfectly suited for applications such as LED, motor control, H-bridge and power converters.

Serial Peripherals

There are several serial devices on-board, which are all CIPs. The USART supports full-duplex communication, asynchronous and synchronous operation and one-wire configurations. The USART can be set in Serial Peripheral Interface (SPI) master mode and used for SPI communication. The dedicated SPI is a high-speed full duplex synchronous data transfer interface using three or four pins. It allows fast communication. The I2C supports both master and slave modes with address match up to 10-bit in 100k, 400k and 1 Mbit/s. Both modes are SMBus compatible.

Configurable Custom Logic

The Configurable Custom Logic (CCL) is a programmable logic peripheral which can be connected to the device pins, events, or other internal peripherals. This allows the user to eliminate logic gates for glue logic functions on the PCB. Each Lookup Table (LUT) consists of three inputs, a truth table, options synchronizer, filter and edge detector. Each LUT can generate an output that can be routed internally or available on pins. This eliminates the need for external logic and reduces BOM cost.


  • AVR® 8-bit CPU
  • Running at up to 20MHz
  • Single cycle I/O access
  • Two-level interrupt controller
  • Two-cycle hardware multiplier


  • 4/8KB In-system self-programmable Flash memory
  • 128B EEPROM
  • 256/512B SRAM


  • Power-on Reset (POR)
  • Brown-out Detection (BOD)
  • Internal and external clock options:
    • 16/20MHz low power RC
    • 32.768kHz Ultra Low Power (ULP)
    • 32.768kHz external crystal oscillator
  • External clock input
  • Single pin programming and debugging interface (UPDI)

Three Sleep Modes

  • Idle with all peripherals running and mode for immediate wake up time
  • Standby
  • Power Down

I/O and Packages

  • 12 to 22 programmable I/O lines
  • 14-pin SOIC150
  • 20-pin QFN 3x3 and SOIC300
  • 24-pin QFN 4x4

Temperature Ranges

  • -40°C to 105°C within specification

Speed Grades

  • 0-5MHz @ 1.8V – 5.5V
  • 0-10MHz @ 2.7V – 5.5V
  • 0-20MHz @ 4.5V – 5.5V

Featured Documents

  • Product Brief - DS40001744
  • Programming Spec - DS40001738
  • Product Brief - DS40001768
  • Programming Spec - DS40001753


  • One 16-bit Timer/Counter type A with dedicated period register, 3 compare channels (TCA)
  • One 16-bit Timer/Counter type B with input capture (TCB)
  • One 12-bit Timer/Counter type D optimized for control applications (TCD)
  • 16-bit Real Time Counter (RTC) running from external crystal or internal RC oscillator
  • One USART with fractional baud rate generator, autobaud, and start-of-frame detection
  • Master/slave Serial Peripheral Interface (SPI)
  • Master/slave I2C with dual address match up to 1MHz – I2C and SMBUS compliant
  • Configurable Custom Logic (CCL) with two programmable Lookup Tables (LUT)
  • Analog Comparator (AC) with fast propagation delay
  • 10-bit 150ksps Analog to Digital Converter (ADC)
  • 8-bit Digital to Analog Converter (DAC)
  • Automated CRC memory scan
  • Window Watchdog Timer (WDT) with separate on-chip oscillator
  • Peripheral Touch Controller (PTC)(1)
  • Capacitive touch buttons, sliders and wheels
  • Wake-up on touch
  • Driven shield for improved moisture and noise handling performance
  • Six self-capacitance and nine mutual-capacitance channels
  • External interrupt on all general purpose pins