Tiny CPU is a custom “small CPU” design intended for implementation in a CPLD. Such soft CPU cores typically target an FPGA or large CPLD, but the target device for Tiny CPU is the Altera EPM7128, which has just 128 macrocells. This constrains the CPU to a minimal set of features in order to fit. It is an 8-bit CPU with only two registers, and a 10-bit address space. The instruction set is a subset of the 6502 instruction set, with modifications to reflect the smaller address space and number of registers.