Introducing Qomu

• 2 min

Three years ago I announced crowdfunding for Tomu – a microcontroller in your USB port. This project brought to mass-market a tiny Arm Cortex-M0 CPU in a package that fits directly into a USB port. Now you could take a standalone USB project anywhere.

One year later in 2019, we launched Fomu – an FPGA in your USB port. This FPGA had no CPU, so we had to provide one. We shipped with a Risc-V core, and provided users with a way to add their own modules to the core, or to replace or remove the CPU entirely.

Now I’m pleased to announce Qomu, one in collaboration with QuickLogic. Qomu is a CPU + tiny FPGA in a Tomu form factor. Like Tomu and Fomu, Qomu fits inside your USB Type A port. It uses the same basic plastic case as before, and extends the feature set substantially. Qomu sits between the two on the CPU-FPGA spectrum, as it includes functionality from both families.

The CPU core is based on an Arm Cortex-M4F, which includes an FPU and 512 kB of RAM. Half a megabyte of RAM and an 80 MHz CPU core let you do a lot, and I’m excited to see what people do with this port-sized powerhouse.

Unlike many existing microcontrollers, the EOS-S3 MCU doesn’t include onboard flash storage. Instead, we rely on the same SPI flash device we used in Fomu. This 2 MB SPI provides the boot medium, as well as additional storage for user programs.

Qomu includes a small FPGA inside the EOS-S3 package. This FPGA includes 891 logic cells, where each cell includes 22 inputs and three outputs allowing for some desnse packing of logic.

FPGAs are nothing without tooling, and until now the open source FPGA tooling has all been based on reverse-engineered or reimplemented bitstream synthesizers. QuickLogic is the first FPGA to have open tooling that is supported directly by the vendor. No license files to worry about, no region locking or magical blessed build machines – just download the toolchain and start synthesizing.

As before, the hardware itself is also open source, and is available on GitHub.

Qomu is crowdfunding now on CrowdSupply – preorder yours today!