Today’s embedded system designer has a number of processor choices for creating customized single-chip, processor-based systems. The budget-constrained designer who is not tied to a particular processor or ISA has the option of using one of the freeware RISC microprocessors available on www.opencores.org. This white paper is intended to give designers a look into the eASIC Nextreme Structured ASIC design flow for implementing a popular open source design: the OpenCores OR1200 CPU.