LatticeMico32 is a 32-bit microprocessor reduced instruction set computer (RISC) soft core from Lattice Semiconductor optimized for field-programmable gate arrays (FPGAs). It uses a Harvard architecture, which means the instruction and data buses are separate. Bus arbitration logic can be used to combine the two buses, if desired.

LatticeMico32 is licensed under a free (IP) core license. This means that the Mico32 is not restricted to Lattice FPGAs, and can be legally used on any host architecture (FPGA, application-specific integrated circuit (ASIC), or software emulation, e.g., QEMU). It is possible to embed a LatticeMico32 core into Xilinx and Altera FPGAs, in addition to the Lattice Semiconductor parts the LatticeMico32 was developed for. AMD PowerTune uses LatticeMico32.^[1]

The CPU core and the development toolchain are available as source-code, allowing third parties to implement changes to the processor architecture.

Features

• RISC load/store architecture
• 32-bit data path
• 32-bit fixed-size instructions (all instructions are 32 bits, including jump, call and branch instructions.)
• 32 general purpose registers (R0 is typically set to zero by convention, however R0 is a standard register and other values may be assigned to it if so desired.)
• Up to 32 external interrupts
• Configurable instruction set including user defined instructions
• Optional configurable caches (direct-mapped or 2-way set-associative, with a variety of cache sizes and arrangements)
• Optional pipelined memories
• Dual Wishbone memory interfaces (one read-only instruction bus, one read-write data/peripheral bus)
• Memory mapped I/O
• 6 stage pipeline

Toolchain

• GNU Compiler Collection (GCC) – C/C++ compiler; LatticeMico32 support is added in GCC 4.5.0, patches are available for support in GCC 4.4.0
• Binutils – Assembler, linker, and binary utilities; supports LatticeMico32 since version 2.19
• GNU Debugger (GDB) – Debugger
• Eclipse – Integrated development environment (IDE)
• Newlib – C library
• μCos-II, μITRON, RTEMS - real-time operating systems (RTOS)
• μClinux – operating system