BIO: The Bao I/O Coprocessor

BIO is the I/O co-processor in the Baochip-1x, a mostly open source 22nm SoC I helped design. You can read more about the Baochip-1x’s background here, or pick up an evaluation board at Crowd Supply. In this post, I’ll talk about the origins of the BIO, starting by working through a detailed study of the Raspberry Pi PIO as a reference, before diving into the architecture of the BIO. I’ll then work through three programming examples of the BIO, two in assembly and one in C. If all you’re interes...