Getting Stated with ATtiny Configurable Custom Logic (CCL)

In the Microchip tinyAVR 0-series, 1-series, and 2-series we see Configurable Custom Logic (CCL) among the Core Independent Peripherals (CIP) available on the chip. In this YouTube video [Grug Huhler] …read more

May 3, 2025 - 12:19

Getting Stated with ATtiny Configurable Custom Logic (CCL)

Configurable Custom Logic (CCL) Block Diagram.

In the Microchip tinyAVR 0-series, 1-series, and 2-series we see Configurable Custom Logic (CCL) among the Core Independent Peripherals (CIP) available on the chip. In this YouTube video [Grug Huhler] shows us how to make your own digital logic in hardware using the ATtiny CCL peripheral.

If you have spare pins on your tinyAVR micro you can use them with the CCL for “glue logic” and save on your bill of materials (BOM) cost. The CCL can do simple to moderately complex logic, and it does it without the need for support from the processor core, which is why it’s called a core independent peripheral. A good place to learn about the CCL capabilities in these tinyAVR series is Microchip Technical Brief TB3218: Getting Started with Configurable Custom Logic (CCL) or if you need more information see a datasheet, such as the ATtiny3226 datasheet mentioned in the video.

A tinyAVR micro will have one or two CCL peripherals depending on the series. The heart of the CCL hardware are two Lookup Tables (LUTs). Each LUT can map any three binary inputs into one binary output. This allows each LUT to be programmed with one byte as simple 2-input or 3-input logic, such as NOT, AND, OR, XOR, etc. Each LUT output can optionally be piped through a Filter/Sync function, an Edge Detector, and a Sequencer (always from the lower numbered LUT in the pair). It is also possible to mask-out LUT inputs.

In the source code that accompanies the video [Grug] includes a demonstration of a three input AND gate, an SR Latch using the sequencer, an SR Latch using feedback, and a filter/sync and edge detection circuit. The Arduino library [Grug] uses is Logic.h from megaTinyCore.

We have covered CIP and CCL technology here on Hackaday before, such as back when we showed you how to use an AVR microcontroller to make a switching regulator.