Paul van Gerven
3 March

Imec and partners have developed a missing component for the flexible electronics toolkit: a microprocessor capable of doing elaborate computations. Teaming up with KU Leuven and flexible electronics foundry Pragmatic, the research institute demonstrated the world’s fastest 8-bit flexible processor capable of running real-time complex assembly code.

The chip, presented at the 2022 ISSCC this week, is made in 0.8µm indium-gallium-zink-oxide (IGZO) technology, integrating roughly 16,000 transistors on a 24.9 mm2 substrate. Its maximum operating speed is 71.4 kHz, during which the circuit consumes 134.9 mW. At a more leisurely 10 kHz, the power consumption is 11.6 mW. To demonstrate the processor’s capabilities, Imec showcased it running the famous Snake game.

Imec flexible microprocessor

In developing the new chip, Imec addressed major challenges related to the design of unipolar systems. “Metal-oxide thin-film transistors based on IGZO are inherently n-type. This results in circuits with a higher static power consumption compared to complementary technologies. To address this, we created our own design flow starting from the open-source file of the MOS6502 microprocessor – one of the most influential microprocessors ever designed,” comments Kris Myny, principal scientist at Imec.

“We engineered the number of cells and logic gates to obtain the most optimal design for our flexible 6502 microprocessor in terms of area, power and speed – using pseudo-CMOS as our logic family. This unique design flow allowed us to create a new standard cell library for metal-oxide thin-film technology that can be used to innovate applications based on metal-oxide thin-film technology,” Myny adds.