CD16 Soft CPU, A synthesizable 16-bit CPU with development tools.
The CD16 is a cross between a stack CPU and a register CPU, a 16-bit chip, designed to fit the back ends of Forth and C compilers, so the architecture lends itself to efficient execution of both Forth and C.
On a Xilinx Spartan2, expect 20 MHz and 350 LUTs. Or, half of a XC3S50 at 40 MHz.