parameter   STATE_FETCH_INSTRUCTION_LO  =   4'b0000,
                STATE_FETCH_INSTRUCTION_LO_READ =   4'b0001,

                STATE_FETCH_INSTRUCTION_HI  =   4'b0010,
                STATE_FETCH_INSTRUCTION_HI_READ =   4'b0011,

                STATE_FETCH_INSTRUCTION_DECODE = 4'b0100,

                STATE_INSTRUCTION_MOVE  =   4'b0101,
                STATE_INSTRUCTION_MOVE_IMMEDIATE    =   4'b0110,
                STATE_INSTRUCTION_BRANCH    =   4'b0111,
                STATE_INSTRUCTION_JUMP  =   4'b1000,
                STATE_INSTRUCTION_MATH  =   4'b1001,

                STATE_CLASS_MOVE_READ_MEM_CLK   = 4'b1010,
                STATE_CLASS_MOVE_READ_MEM   = 4'b1011,
                STATE_CLASS_MOVE_WRITE_MEM_CLK  = 4'b1100,
                STATE_CLASS_MOVE_WRITE_MEM  = 4'b1101,
                STATE_CLASS_NOP         = 4'b1110;