ATtiny microcontrollers specifically exclude various common features, such as: USB peripheral, DMA controller, crypto engine, or an external memory bus. The following table summarizes common features of the ATtiny microcontrollers, for easy comparison. This table is not meant to be an unabridged feature list. ;Notes :* Package column - the number after the dash is the number of pins on the package.
DIP packages in this table are row-to-row.
SOwww means
SOIC package with a case width of 'www' in
thousandth of an inch. Though some package types are known by more than one name, a common name was chosen to make it easier to compare packages. :* UART/I²C/SPI columns - means a dedicated peripheral, * means a multi-feature peripheral that is chosen by setting configuration bits. Most USART peripherals support a minimum choice between UART or SPI, where as some might support additional choices, such as
LIN,
IrDA,
RS-485. :* Timers column - more recent families have wider timers and may allow chaining two 16-bit timers to do 32-bit capture. RTT is a 16-bit Real Time Timer that is driven by a 32.768KHz clock, though Microchip calls it RTC for Real Time Counter (easily confused to mean Real Time Clock). :* ADC pins column - the total number of analog channels that are accessible via pins that multiplex into the ADC input. Most parts have one ADC, a few have two ADC. :* Pgm/Dbg column - flash programming and debugging protocols:
HVPP means High Voltage Parallel Programming 12V protocol,
HVSP means High Voltage Serial Programming 12V protocol,
ISP means
In-System Programmable protocol, uses SPI to program the internal flash.
TPI is Tiny Programming Interface.
dW means
debugWIRE protocol.
UPDI means Unified Program and Debug Interface protocol (newest). ;Abbreviations • TWI: Many of Atmels microcontrollers contain built-in support for interfacing to a two-wire bus, called Two-Wire Interface. This is essentially the same thing as the
I²C interface by Philips, but that term is avoided in Atmel's documentation due to trademark issues. • USI: Universal Serial Interface (not to be confused with
USB). The USI is a multi-purpose hardware communication module. With appropriate software support, it can be used to implement an
SPI,
I²C or
UART interface. USART peripherals have more features than USI peripherals. ==Timeline==