EYE on NPI - AVR DD Family of Microcontrollers #Digikey #EYEonNPI @DigiKey @microchipmakes @adafruit
Channel: Adafruit Industries
Date: 25/08/2022

This week's EYE ON NPI is a throwback to the 8-bit era, with a new spin on the classic AVR microcontrollers we've loved for decades: it's Microchip's AVR® DD Family of Microcontrollers (https://www.digikey.com/en/product-highlight/m/microchip-technology/avr-dd-family-of-microcontrollers), a powerful update to the powerful and low-power AVR RISC core that came from Atmel. While many folks may be moving to Cortex M0 or RISC-V chipsets to get 32-bit performance, there's still a lot of demand and use for 8-bit microcontrollers. Cost, simplicity, reliability, code-size, and power usage can all be better on 8-bit. If you're only on a 32-bit micro because of peripherals that tend to come with the fancier chips, you might be surprised by what the AVR DD family has to offer.

For example, these chips have external interrupts on (just about all) the GPIO pins. There's four 16-bit timers plus one 12-bit (that's *five* total timers!), SPI & I2C, two UARTs, a 10-bit DAC, and 12-bit input ADC that's muxed to almost every pin. In particular, the high-bit ADC and DAC are a little unusual to see in an 8-bit platform. (https://ww1.microchip.com/downloads/aemDocuments/documents/MCU08/ProductDocuments/DataSheets/AVR32-16DD20-14-Prel-DataSheet-DS40002413.pdf)

There's also some funky MCP-specific peripherals that can help reduce BOM cost. For example, CCL/LUT is a peripheral that allows you to make custom logic-lookup-tables for making simple - but very very fast -  multi-input logic gates that can use interrupts or peripherals as input. (http://ww1.microchip.com/downloads/en/AppNotes/TB3218-Getting-Started-with-CCL-90003218A.pdf) For example, you can make a SR latch, logic gate, or Manchester encoder - you can think of it as like a 'micro' PIO or CPLD.

MVIO is a new capability that we haven't seen before, where an IO port can run at a different logic level - either higher or lower than the VCC power. This allows easy bi-directional interfacing of SPI/I2C/GPIO to 3V logic from 5V, or vice versa, without the use of level shifting! (http://ww1.microchip.com/downloads/en/Appnotes/GettingStarted-MVIO-AVRDB-DS90003287A.pdf) Perfect if you want to run this main core at 5V for speed and signal strength, but have some 3V sensors to interface to, or run the core at 1.8V for power and IO but have a 3.4V LED you want to light up.

Clock rate is up to 24 MHz, can be powered from 1.8 to 5.5V - it's exceedingly rare to find 5V ARM chips -  and have FLASH, SRAM, EEPROM and NVM. EEPROM in particular is not common on ARM chips, and some don't even have built in Flash. So think of this as a compact li'l chip with pretty much everything you need to get a product out the door, with a range of memory sizes and physical packages from QFN to DIP! (http://ww1.microchip.com/downloads/en/DeviceDoc/AVR-DD-Product-Brief-DS40002215A.pdf) It's nice to see Microchip is still innovating the AVR line, to make better 8-bit micros that power the electronics around us.

For programming, of course you can use MPLAB IDE but we like Arduino compatibility and SpenceKonde's DxCore (https://github.com/SpenceKonde/DxCore) looks like it's adding or added AVR DD support, so you can quickly get going with compiling code and using the basic peripherals in just a few minutes!

Best of all, the AVR DD family of parts (https://www.digikey.com/short/m4qb8wf8) are totally in stock at Digi-Key right now for immediate shipment. There's SOIC, SSOP and QFN packages with up to 64KB flash / 8 KB RAM, all for about $1.50 in individuals, $1 in qty. If you're looking for an alternative to the ATmega328, this is a nice step up. We recommend getting started with the AVR DD Curiosity Nano board which is breadboard compatible and has everything needed to get started. (https://www.digikey.com/short/10n70tmc) Order today and you can be MVIOing towards your next AVR 8-bit based product by tomorrow afternoon!