  We proposes a platform which can generate hardware/software description based
on flexible in-struction set architectures (ISAs). The platform takes advantage
of the flexibility of field pro-grammable gate array (FPGA) to design many
micro control units (MCUs) based on different ISAs. The platform can generate
many ISAs, MCUs, and Assemblers according to a pre-defined ISA and user
applications. Although the MCU performance is not optimized, the FPGA shows a
great potential on resource reduction and enough performance at very low system
clock rate. The flexible ISA has shown great importance for the design targeted
to specific purpose. We also show a case study of the proposed flexible
ISA-based FPGA-MCU. It can control many specifi-cally designed hardware IPs and
a customized multi-task OS with tasks. Not only the case works correctly, but
also the proposed FPGA-MCU of the case is flexible with reduced FPGA resources,
low cost, and within time constraints.
