Tiny Tapeout #1 included a 4-bit CPU, a 6-bit CORDIC, an FPGA, and other tiny circuits. It seemed like an SRAM was missing, so this is my attempt to remedy that in Tiny Tapeout #2. This circuit also has an additional feature to stream internal data without continuously updating the address, enabling use as a signal generator.
The circuit in this repository has a 4-bit address/data input and 8-bit output. Due to circuit area limitations and input width, only 16 bytes are addressable. There are three modes: Write, Read, and Stream. The diagram below demonstrates how to use the SRAM in each mode. Because there are only eight pins for input and four of the pins are used for signaling, the remaining four input addr/data pins define the data and address over three cycles. Commit will set the internal shift register value to memory at the address provided, or when using the Stream mode, set the starting index or address to stream from.
TinyTapeout is an educational project that aims to make it easier and cheaper than ever to get your digital designs manufactured on a real chip!
Go to https://tinytapeout.com for instructions!