PicoBlaze

PicoBlaze is the designation of a series of three free soft processor cores from Xilinx for use in their FPGA and CPLD products. They are based on a RISC architecture of 8 bits and can reach speeds up to 100 MIPS on the Virtex 4 FPGA's family. The processors have an 8-bit address and data port for access to a wide range of peripherals. The license of the cores allows their free use, albeit only on Xilinx devices, and they come with development tools. Third party tools are available from Mediatronix and others. Also PacoBlaze, a behavioral and device independent implementation of the cores exists and is released under the BSD License.

The PicoBlaze design was originally named KCPSM which stands for "Constant(K) Coded Programmable State Machine" (formerly "Ken Chapman's PSM"). Ken Chapman was the Xilinx systems designer who devised and implemented the microcontroller.

When instantiating a PicoBlaze microcontroller in VHDL, the respective KCPSM component name must be used. For example, for a PicoBlaze3 processor:

component kcpsm3 is
  port (
    address       : out std_logic_vector(9 downto 0);
    instruction   : in std_logic_vector(17 downto 0);
    port_id       : out std_logic_vector(7 downto 0);
    write_strobe  : out std_logic;
    out_port      : out std_logic_vector(7 downto 0);
    read_strobe   : out std_logic;
    in_port       : in std_logic_vector(7 downto 0);
    interrupt     : in std_logic;
    interrupt_ack : out std_logic;
    reset         : in std_logic;
    clk           : in std_logic
    );
end component;

External links

• PicoBlaze on the Xilinx website
• PicoBlaze product brief
• PicoBlaze user manual
• TechXclusives: Creating Embedded Microcontrollers (Programmable State Machines) PDF
• PicoBlaze user resources
• Open source Picoblaze assembler
• pBlazIde, an open source assembler IDE for Windows
• kpicosim, an open source assembler IDE for Linux
• openPICIDE, an open source assembler IDE for Linux, MAC and Windows
• PacoBlaze: an open source synthesizable and behavioral Verilog clone of PicoBlaze
• Implementation of picoblaze in LabVIEW FPGA on the Xilinx Spartan 3E Starter board