_CPU_MAIN.vhd

Library IEEE;
USE IEEE.std_logic_1164.all;
entity CPU_MAIN is
port (
GLOBAL_ENABLE : in std_logic;
GLOBAL_RESET : in std_logic;
GLOBAL_INITAIL : in std_logic := '0' ;
CLK : in std_logic ;
OUTPORT : out std_logic_vector(31 DOWNTO 0);
 FLAGS: inout std_logic_vector (2 downto 0)  := (OTHERS => '0') 
);
end entity;

architecture CPU_MAIN_ARCH of CPU_MAIN is
component control_unit is
port (
-- INPUTS 
IR : in std_logic_vector (31 downto 0);

-- OUTPUTS (CONTROL SIGNALS):
OUT_SIG : out std_logic ;
IN_SIG  : out std_logic ;
ALU_OPR : out std_logic_vector (3 downto 0);
ALU_SRC : out std_logic ;
REG_DST : out std_logic ;
MEM_TO_REG : out std_logic ;
FETCH_EN : out std_logic ;
DATA_EN : out std_logic ;
ALU_EN :  out std_logic ;
BR_EN :  out std_logic ;
MEM_WR_EN :  out std_logic ;
MEM_RD_EN : out std_logic ;
SWAP : out std_logic ;
IN_SP  :  out std_logic ;
SP_INC_DEC : out std_logic ;
EA_IMM_SEL : out std_logic ;
JMP : out std_logic ;
JZ : out std_logic ;
FUNC : out std_logic ;
RTI : out std_logic ;
WB : out std_logic ;
FLUSH_JMP : out std_logic ;
FLUSH_FUNC : out std_logic ;
FLUSH_JZ  : out std_logic 
);
end component;

component decode_stage is
port (
-- INPUTS
ENABLE : in std_logic ;
RESET : in std_logic ;
CLK :  in std_logic ;
IR : in std_logic_vector (31 downto 0);
EA_IMM_SEL : in std_logic ;
WR_ADDRESS_1 : in std_logic_vector (2 downto 0);
WR_ADDRESS_2 : in std_logic_vector (2 downto 0);
WR_DATA_1 : in std_logic_vector (31 downto 0);
WR_DATA_2 : in std_logic_vector (31 downto 0);
WR_EN_1 : in std_logic ;
WR_EN_2 : in std_logic ;
SWAP_EN : in std_logic ;
REG_DST : in std_logic ;

-- OUTPUTS
RD_DATA_1 : out std_logic_vector (31 downto 0);
RD_DATA_2 : out std_logic_vector (31 downto 0);

-- HOLDING IMMEDIATE VALUE OR EXTENDED EFFECTIVE ADDRESS
EA_IMM_DATA : out std_logic_vector (31 downto 0);
Rdst_address : out std_logic_vector (2 downto 0);
Rsrc1_address : out std_logic_vector (2 downto 0);
Rsrc2_address  : out std_logic_vector (2 downto 0)

);
end component;       

component fetch_buffer is 
port(    
    clk : in std_logic ; 
	reset_global : in std_logic ; 
    enable_global : in std_logic ; 
    IR_enable :in std_logic;
    IR_reset : in std_logic;
    IR_in : in std_logic_vector(31 downto 0);
    IR_out	: out std_logic_vector(31 downto 0);
    PC_enable :in std_logic;
    PC_reset : in std_logic;
    PC_in : in std_logic_vector(31 downto 0);
    PC_out	: out std_logic_vector(31 downto 0);
    INT_in 	: in std_logic ;
    INT_out : out std_logic   
);
end component;

component fetch_stage is
    generic (n:integer := 16);
    port(       
            initial : in std_logic;
            Clk ,reset : in std_logic;
            correct_branch_address,address2,mux8_output,read_data_1,predicted_branch_address : in std_logic_vector(15 downto 0);
            miss_prediction,int_fsm,func,branch,branch_prediction,stalling : in std_logic;                    
            hold_to_complete_out :out std_logic;
            out_IR :out  std_logic_vector(31 downto 0);    
            out_PC :out  std_logic_vector(31 downto 0)    
        );
end component;

component ID_EX is
port (
-- INPUTS 
ENABLE : in std_logic ;
RESET : in std_logic;
CLK : in std_logic;
STALL_SIG : in std_logic ; 
-- CONTROL SIGNALS
PC : in std_logic_vector (31 downto 0);
Rdst : in std_logic_vector (31 downto 0);
Rsrc1 : in std_logic_vector (31 downto 0);
Rsrc2 : in std_logic_vector (31 downto 0);
EA_IMM_DATA : in std_logic_vector (31 downto 0);
Rdst_address : in std_logic_vector (2 downto 0);
Rsrc1_address : in std_logic_vector (2 downto 0);
Rsrc2_address : in std_logic_vector (2 downto 0);
OUT_SIG : in std_logic ;
IN_SIG  : in std_logic ;
ALU_OPR : in std_logic_vector (3 downto 0);
ALU_SRC : in std_logic ;
REG_DST : in std_logic ;
MEM_TO_REG : in std_logic ;
FETCH_EN : in std_logic ;
DATA_EN : in std_logic ;
ALU_EN :  in std_logic ;
BR_EN :  in std_logic ;
MEM_WR_EN :  in std_logic ;
MEM_RD_EN : in std_logic ;
SWAP : in std_logic ;
IN_SP  :  in std_logic ;
SP_INC_DEC : in std_logic ;
EA_IMM : in std_logic ;
JMP : in std_logic ;
JZ : in std_logic ;
FUNC : in std_logic ;
RTI : in std_logic ;
WB : in std_logic ;
FLUSH_JMP : in std_logic ;
FLUSH_FUNC : in std_logic ;
FLUSH_JZ  : in std_logic ;
IR_OPCODE : in std_logic_vector (4 downto 0);
INTR 	: in std_logic ; 
-- OUTPUTS
OUT_CONTROL_SIGNALS : out std_logic_vector (27 downto 0);
PC_OUT : out std_logic_vector (31 downto 0);
Rdst_OUT : out std_logic_vector (31 downto 0);
Rsrc1_OUT : out std_logic_vector (31 downto 0);
Rsrc2_OUT : out std_logic_vector (31 downto 0);
EA_IMM_DATA_OUT : out std_logic_vector (31 downto 0);
Rdst_address_OUT : out std_logic_vector (2 downto 0);
Rsrc1_address_OUT : out std_logic_vector (2 downto 0);
Rsrc2_address_OUT : out std_logic_vector (2 downto 0);
IR_OPCODE_OUT : out std_logic_vector (4 downto 0)
);
end component;


-------------------------- Execute Stage component -----------------------------

component Execute_Stage_Entity is 
port(
--ID/EX INPUTS
IDEX_CONTROL_SIGNALS :in std_logic_vector (27 downto 0);
IDEX_PC :in  std_logic_vector (31 downto 0);
IDEX_Rdst :in  std_logic_vector (31 downto 0);
IDEX_Rsrc1 :in  std_logic_vector (31 downto 0);
IDEX_Rsrc2 :in  std_logic_vector (31 downto 0);
IDEX_EA_IMM_DATA :in  std_logic_vector (31 downto 0);
IDEX_Rdst_address :in  std_logic_vector (2 downto 0);
IDEX_Rsrc1_address :in  std_logic_vector (2 downto 0);
IDEX_Rsrc2_address :in  std_logic_vector (2 downto 0); 
ID_EX_OPCODE : in std_logic_vector (4 downto 0); 

--EX/MEM Outputs
EXMEM_ALU_RESULT:out  std_logic_vector (31 downto 0);
EXMEM_CONTROL_SIGNALS :out std_logic_vector (27 downto 0);
EXMEM_PC :out  std_logic_vector (31 downto 0);
EXMEM_Rdst :out  std_logic_vector (31 downto 0);
EXMEM_Rsrc2 :out  std_logic_vector (31 downto 0);
EXMEM_Rdst_address :out  std_logic_vector (2 downto 0);
EXMEM_Rsrc1_address :out  std_logic_vector (2 downto 0);
EXMEM_Rsrc2_address :out  std_logic_vector (2 downto 0); 
EX_MEM_OPCODE : out std_logic_vector (4 downto 0); 

--Forwarding data
Mem_Forwarding , WB_Forwarding: in std_logic_vector (31 downto 0) ;

--Forwarding unit selectors
Forwarding_Selectors1,
Forwarding_Selectors2 : in std_logic_vector (1 downto 0) ;

--In Port Data
In_Port: in std_logic_vector (31 downto 0) ;

--flags
FlagsIn : in std_logic_vector (2 downto 0)  ; 
FlagsOut : out std_logic_vector (2 downto 0)  ; 

--clk , enable , reset
clk,
Enable,
Reset: in std_logic);

end component Execute_Stage_Entity;

component EX_Buffer_Entity is 
port(
EXMEM_ALU_RESULT_IN:in  std_logic_vector (31 downto 0);
EXMEM_CONTROL_SIGNALS_IN :in std_logic_vector (27 downto 0);
EXMEM_PC_IN :in  std_logic_vector (31 downto 0);
EXMEM_Rdst_IN :in  std_logic_vector (31 downto 0);
EXMEM_Rsrc2_IN :in  std_logic_vector (31 downto 0);
EXMEM_Rdst_address_IN :in  std_logic_vector (2 downto 0);
EXMEM_Rsrc1_address_IN :in  std_logic_vector (2 downto 0);
EXMEM_Rsrc2_address_IN :in  std_logic_vector (2 downto 0); 
EXMEM_OP_CODE_IN  :in  std_logic_vector (4 downto 0); 

EXMEM_ALU_RESULT_OUT:out  std_logic_vector (31 downto 0);
EXMEM_CONTROL_SIGNALS_OUT :out std_logic_vector (27 downto 0);
EXMEM_PC_OUT :out  std_logic_vector (31 downto 0);
EXMEM_Rdst_OUT :out  std_logic_vector (31 downto 0);
EXMEM_Rsrc2_OUT :out  std_logic_vector (31 downto 0);
EXMEM_Rdst_address_OUT :out  std_logic_vector (2 downto 0);
EXMEM_Rsrc1_address_OUT :out  std_logic_vector (2 downto 0);
EXMEM_Rsrc2_address_OUT :out  std_logic_vector (2 downto 0); 
EXMEM_OP_CODE_OUT  :out  std_logic_vector (4 downto 0); 

Wr,clk,reset : in std_logic);
end component EX_Buffer_Entity;


-------------------------- Memory Stage component -----------------------------
COMPONENT MemoryEnt IS
    PORT(
              --  For entity
            Clk,Enable: IN std_logic;

            -- Signals
            ControlSignals : IN std_logic_vector(27 DOWNTO 0);
            Int,Call: IN std_logic;

            -- Addresses 
            PC,SP,ALUResult: IN std_logic_vector(31 DOWNTO 0);


            RDesData  : IN std_logic_vector(31 DOWNTO 0);
            RSrc2Data : IN std_logic_vector(31 DOWNTO 0);

            RDes : IN std_logic_vector(2 DOWNTO 0);
            RSrc1 : IN std_logic_vector(2 DOWNTO 0);
            RSrc2 : IN std_logic_vector(2 DOWNTO 0);

            -- Data
            DataRead2: IN std_logic_vector(31 DOWNTO 0);

	    -- Data
  	   OPCODE:IN std_logic_vector(4 DOWNTO 0);

            -- Outputs
            RDesDataOut  : OUT std_logic_vector(31 DOWNTO 0);
            RSrc2DataOut : OUT std_logic_vector(31 DOWNTO 0);

            RDesOut : OUT std_logic_vector(2 DOWNTO 0);
            RSrcOut1 : OUT std_logic_vector(2 DOWNTO 0);
            RSrcOut2 : OUT std_logic_vector(2 DOWNTO 0);

            MemOut: OUT std_logic_vector(31 DOWNTO 0);
            SPOut: OUT std_logic_vector(31 DOWNTO 0);
            ALUResultOut: OUT std_logic_vector(31 DOWNTO 0);
            ControlSignalsOut :OUT std_logic_vector(27 DOWNTO 0);
            OPCODEOut:Out std_logic_vector(4 DOWNTO 0)

        );
END COMPONENT;

-------------------------- Memory Buffer ----------------------------

COMPONENT MemBufferEnt IS
    PORT ( 
            -- Inputs
            Clk,Reset,Enable : IN std_logic;
            ControlSignals : IN std_logic_vector(27 DOWNTO 0);
            SP,MemOut,ALUResult : IN std_logic_vector(31 DOWNTO 0);

            RDesData  : IN std_logic_vector(31 DOWNTO 0);
            RSrc2Data : IN std_logic_vector(31 DOWNTO 0);

            RDes : IN std_logic_vector(2 DOWNTO 0);
            RSrc1 : IN std_logic_vector(2 DOWNTO 0);
            RSrc2 : IN std_logic_vector(2 DOWNTO 0);

            OP_CODE : IN std_logic_vector(4 DOWNTO 0);

            -- Outputs
            RDesDataOut  : OUT std_logic_vector(31 DOWNTO 0);
            RSrc2DataOut : OUT std_logic_vector(31 DOWNTO 0);

            RDesOut : OUT std_logic_vector(2 DOWNTO 0);
            RSrcOut1 : OUT std_logic_vector(2 DOWNTO 0);
            RSrcOut2 : OUT std_logic_vector(2 DOWNTO 0);
            

            ControlSignalsOut: OUT std_logic_vector(27 DOWNTO 0);
            SPOut,MemOutOut,ALUResultOut : OUT std_logic_vector(31 DOWNTO 0);

            OP_CODE_OUT : OUT std_logic_vector(4 DOWNTO 0)
        );
END COMPONENT;

--------------------------- WB Stage --------------------------

COMPONENT WBEnt IS
    PORT(
            --  For entity
            Clk,Enable: IN std_logic;

            -- Signals
            ControlSignals : IN std_logic_vector(27 DOWNTO 0);
            Int: IN std_logic;

            -- SP 
            SP : IN std_logic_vector(31 DOWNTO 0);

            -- Data
            MemOut,ALUResult: IN std_logic_vector(31 DOWNTO 0);

            RDesData  : IN std_logic_vector(31 DOWNTO 0);
            RSrc2Data : IN std_logic_vector(31 DOWNTO 0);

            RDes : IN std_logic_vector(2 DOWNTO 0);
            RSrc1 : IN std_logic_vector(2 DOWNTO 0);
            RSrc2 : IN std_logic_vector(2 DOWNTO 0);

            -- Outputs
            RDesDataOut  : OUT std_logic_vector(31 DOWNTO 0);
            RSrc2DataOut : OUT std_logic_vector(31 DOWNTO 0);

            RDesOut : OUT std_logic_vector(2 DOWNTO 0);
            RSrcOut1 : OUT std_logic_vector(2 DOWNTO 0);
            RSrcOut2 : OUT std_logic_vector(2 DOWNTO 0);

            ControlSignalsOut : OUT std_logic_vector(27 DOWNTO 0);
            IntOut : OUT std_logic;
            Mux10Out, SPOut : OUT std_logic_vector(31 DOWNTO 0)

            -- WRE : OUT std_logic
        );
END COMPONENT;

------------------------Forwarding unit--------------------------

component Forwarding_Unit_Entity is 
port(
EX_MEM_Rdst_Address,
MEM_WB_Rdst_Address,
ALU_Rsrc1_Address,
ALU_Rsrc2_Address: in std_logic_vector (2 downto 0);

EX_MEM_OPCODE,
MEM_WB_OPCODE,
ALU_OPCODE : in std_logic_vector(4 downto 0);

Rsrc1_Selector,
Rsrc2_Selector : out std_logic_vector(1 downto 0)

);
end component Forwarding_Unit_Entity;

-------------------Hazard detection unit-------------------------
component Hazard_Detection_Unit_Entity is
    port(
        --inputs
        IF_ID_OPCODE,
        ID_EX_OPCODE,
        EX_MEM_OPCODE : in std_logic_vector(4 downto 0);    

        IF_ID_Rsrc1,
        IF_ID_Rsrc2,
        IF_ID_Rdst : in std_logic_vector(2 downto 0);

        ID_EX_Rsrc1,
        ID_EX_Rsrc2,
        ID_EX_Rdst : in std_logic_vector(2 downto 0);

        EX_MEM_Rsrc1,
        EX_MEM_Rsrc2,
        EX_MEM_Rdst : in std_logic_vector(2 downto 0);
    	
	clk : in std_logic;

        --outputs
        Stall,
        IF_ID_Write_Enable :out std_logic
    );
end component;

-------------------------------tri state-------------------------------

COMPONENT TriStateEnt is
    Port(
    EN : in std_logic;
    X : IN std_logic_vector(31 downto 0);
    F : OUT std_logic_vector(31 downto 0)
);
END COMPONENT;
 component reg is 
    generic (n:integer := 16);
    port(	clk : in std_logic ; 
        reset : in std_logic ; 
        enable : in std_logic ; 
        d	: in std_logic_vector(n-1 downto 0);
        q	: out std_logic_vector(n-1 downto 0)
    );
    end component;   

COMPONENT TriStateSPEnt is
    Port(
    EN : in std_logic;
    X : IN std_logic_vector(31 downto 0);
    F : OUT std_logic_vector(31 downto 0)
);
END COMPONENT;

COMPONENT Mux21Ent IS
generic (n:integer := 16);
PORT ( 
        s0: IN STD_LOGIC ;
        IN0,IN1 : IN std_logic_vector(n-1 DOWNTO 0);
        F : OUT std_logic_vector(n-1 DOWNTO 0)
    );
END COMPONENT;
-----------------------------------------------------------------------
signal MAIN_INTERRUPT : std_logic := '0';
--------------------   SIGNALS   ------------------------
signal FS_IR :  std_logic_vector (31 downto 0) ;
signal FS_PC :  std_logic_vector (31 downto 0);
--------------------    IF/ID   ----------------------------
signal IFID_IR :  std_logic_vector (31 downto 0);
signal IFID_PC :  std_logic_vector (31 downto 0);

--------------------------------------------------------
--------------------    CU   ----------------------------
signal CU_OUT_SIG : std_logic ;
signal CU_IN_SIG : std_logic ;
signal CU_ALU_OPR : std_logic_vector (3 downto 0) ;
signal CU_ALU_SRC : std_logic ;
signal CU_REG_DST : std_logic ;
signal CU_MEM_TO_REG : std_logic ;
signal CU_FETCH_EN : std_logic ;
signal CU_DATA_EN : std_logic ;
signal CU_ALU_EN : std_logic ;
signal CU_BR_EN : std_logic ;
signal CU_MEM_WR_EN : std_logic ;
signal CU_MEM_RD_EN : std_logic ;
signal CU_SWAP : std_logic ;
signal CU_IN_SP : std_logic ;
signal CU_SP_INC_DEC : std_logic ;
signal CU_EA_IMM_SEL : std_logic ;
signal CU_JMP : std_logic ;
signal CU_JZ : std_logic ;
signal CU_FUNC : std_logic ;
signal CU_RTI : std_logic ;
signal CU_WB : std_logic ;
signal CU_FLUSH_JMP : std_logic ;
signal CU_FLUSH_FUNC : std_logic ;
signal CU_FLUSH_JZ : std_logic ;
------------------------------------------------------------

--------------------    ID/EX   ----------------------------
signal IDEX_OUT_CONTROL_SIGNALS : std_logic_vector (27 downto 0);
signal IDEX_PC_OUT :  std_logic_vector (31 downto 0);
signal IDEX_Rdst_OUT :  std_logic_vector (31 downto 0);
signal IDEX_Rsrc1_OUT :  std_logic_vector (31 downto 0);
signal IDEX_Rsrc2_OUT :  std_logic_vector (31 downto 0);
signal IDEX_EA_IMM_DATA_OUT :  std_logic_vector (31 downto 0);
signal IDEX_Rdst_address_OUT :  std_logic_vector (2 downto 0);
signal IDEX_Rsrc1_address_OUT :  std_logic_vector (2 downto 0);
signal IDEX_Rsrc2_address_OUT :  std_logic_vector (2 downto 0); 
signal IDEX_IR_OPCODE_OUT:  std_logic_vector (4 downto 0); 
------------------------------------------------------------




--------------------    MEM/WB   ----------------------------
signal WB_WR_ADDRESS_1 :  std_logic_vector (2 downto 0);
signal WB_WR_ADDRESS_2 :  std_logic_vector (2 downto 0);
signal WB_WR_DATA_1  :  std_logic_vector (31 downto 0);
signal WB_WR_DATA_2  :  std_logic_vector (31 downto 0);
signal WB_WR_EN_1  :  std_logic;
signal WB_WR_EN_2 :  std_logic;
signal WB_SWAP_EN :  std_logic;


------------------- DECODE STAGE ---------------------------
signal EAIMM_MUXOP_DS : std_logic_vector (31 downto 0);
signal DS_RD_DATA_1_OUT,DS_RD_DATA_2_OUT : std_logic_vector (31 downto 0);

---------------------  GLOBAL ------------------------------
signal GLOBAL_PC :  std_logic_vector (31 downto 0);
signal ZERO_LOGIC_16 : std_logic_vector(15 downto 0):="0000000000000000";
------------------------------------------------------------
----

-------------------Hazard detection unit----------------------
Signal Hazard_Detection_Stall,
       Hazard_Detection_IF_ID_WR_EN : std_logic;

---------------------Execute Stage----------------------------
--Execute Stage output
SIGNAL EXMEM_ALU_RESULT : std_logic_vector(31 DOWNTO 0);
SIGNAL EXMEM_CONTROL_SIGNALS : std_logic_vector(27 DOWNTO 0);
SIGNAL EXMEM_PC  : std_logic_vector(31 DOWNTO 0);
SIGNAL EXMEM_Rdst  : std_logic_vector(31 DOWNTO 0);
SIGNAL EXMEM_Rsrc2  : std_logic_vector(31 DOWNTO 0);
SIGNAL EXMEM_Rdst_address  : std_logic_vector(2 DOWNTO 0);
SIGNAL EXMEM_Rsrc1_address  : std_logic_vector(2 DOWNTO 0);
SIGNAL EXMEM_Rsrc2_address  : std_logic_vector(2 DOWNTO 0);
SIGNAL EX_MEM_OPCODE  : std_logic_vector(4 DOWNTO 0);
--Forwarding data input
SIGNAL Mem_Forwarding : std_logic_vector(31 DOWNTO 0);
SIGNAL WB_Forwarding : std_logic_vector(31 DOWNTO 0);

--Forwarding unit selectors inputs
SIGNAL Forwarding_Selectors1 : std_logic_vector(1 DOWNTO 0);
SIGNAL Forwarding_Selectors2  : std_logic_vector(1 DOWNTO 0);

--In Port Data
SIGNAL In_Port: std_logic_vector (31 downto 0) ;
--In Port Data


--Enable
SIGNAL Execute_EN : std_logic ; 

---------------------------------------------------------------
signal IFID_INTR : std_logic;
-----------------------EX MEM Buffer------------------------------
SIGNAL EXMEM_ALU_RESULT_OUT: std_logic_vector(31 DOWNTO 0);
SIGNAL EXMEM_CONTROL_SIGNALS_OUT : std_logic_vector(27 DOWNTO 0);
SIGNAL EXMEM_PC_OUT : std_logic_vector(31 DOWNTO 0);
SIGNAL EXMEM_Rdst_OUT : std_logic_vector(31 DOWNTO 0);
SIGNAL EXMEM_Rsrc2_OUT : std_logic_vector(31 DOWNTO 0);
SIGNAL EXMEM_Rdst_address_OUT : std_logic_vector(2 DOWNTO 0);
SIGNAL EXMEM_Rsrc1_address_OUT : std_logic_vector(2 DOWNTO 0);
SIGNAL EXMEM_Rsrc2_address_OUT : std_logic_vector(2 DOWNTO 0);
SIGNAL EXMEM_OPCODE_OUT : std_logic_vector(4 DOWNTO 0);

SIGNAL EX_MEM_BUFFER_WRITE : std_logic;

---------------------------------------------------------------

---------------------- Memory Stage -------------------------
SIGNAL RDesDataOutMemory : std_logic_vector(31 DOWNTO 0);
SIGNAL RSrc2DataOutMemory: std_logic_vector(31 DOWNTO 0);

SIGNAL RDesOutMemory : std_logic_vector(2 DOWNTO 0);
SIGNAL RSrcOut1Memory : std_logic_vector(2 DOWNTO 0);
SIGNAL RSrcOut2Memory : std_logic_vector(2 DOWNTO 0);

SIGNAL MemOutMemory: std_logic_vector(31 DOWNTO 0);
SIGNAL SPOutMemory: std_logic_vector(31 DOWNTO 0);
SIGNAL ALUResultOutMemory: std_logic_vector(31 DOWNTO 0);
SIGNAL ControlSignalsOutMemory: std_logic_vector(27 DOWNTO 0);
SIGNAL MEMSTAGE_OPCODE_OUT: std_logic_vector(4 DOWNTO 0);

----------------------- Memory Buffer ------------------------
SIGNAL RDesDataOutBuffer : std_logic_vector(31 DOWNTO 0);
SIGNAL RSrc2DataOutBuffer: std_logic_vector(31 DOWNTO 0);

SIGNAL RDesOutBuffer : std_logic_vector(2 DOWNTO 0);
SIGNAL RSrcOut1Buffer : std_logic_vector(2 DOWNTO 0);
SIGNAL RSrcOut2Buffer : std_logic_vector(2 DOWNTO 0);

SIGNAL ControlSignalsOutBuffer : std_logic_vector(27 DOWNTO 0);
SIGNAL SPOutBuffer : std_logic_vector(31 DOWNTO 0);
SIGNAL MemOutBuffer: std_logic_vector(31 DOWNTO 0);
SIGNAL ALUResultOutBuffer : std_logic_vector(31 DOWNTO 0);
SIGNAL MEMWB_OPCODE_OUT : std_logic_vector(4 DOWNTO 0);

------------------------ WB Stage -----------------------
SIGNAL RDesDataOutWB : std_logic_vector(31 DOWNTO 0);
SIGNAL RSrc2DataOutWB: std_logic_vector(31 DOWNTO 0);

SIGNAL RDesOutWB : std_logic_vector(2 DOWNTO 0);
SIGNAL RSrcOut1WB : std_logic_vector(2 DOWNTO 0);
SIGNAL RSrcOut2WB : std_logic_vector(2 DOWNTO 0);

SIGNAL ControlSignalsOutWB : std_logic_vector(27 DOWNTO 0);
SIGNAL Mux10OutWB : std_logic_vector(31 DOWNTO 0);
SIGNAL SPOutWB : std_logic_vector(31 DOWNTO 0);
SIGNAL IntOutWB : std_logic;
----------------------------- Tri State Signals -------------------------
SIGNAL SPSignal : std_logic;

----------------------------- Test ----------------------------------
SIGNAL ControlSignalSignal : std_logic_vector(27 downto 0);

--------------------------------
signal STALL_TO_FECTH_COMPELETE : std_logic ; 
signal DS_Rdst_address : std_logic_vector (2 DOWNTO 0);
signal DS_Rsrc1_address : std_logic_vector (2 DOWNTO 0);
signal DS_Rsrc2_address : std_logic_vector (2 DOWNTO 0);
--------------------------------
-- SIGNAL SPSofyan : std_logic_vector(31 DOWNTO 0);
SIGNAL SPSofyan : std_logic_vector(31 DOWNTO 0) := "00000000000000000000111110100000";

--------------------------------
Signal BranchFetch , IS_RET,IS_RTI : std_logic;

Signal FlagsWrEnable  : std_logic;
Signal  FlagsInput ,FlagsOutput,ExecuteStageFlags : std_logic_vector(2 downto 0) :=(others => '0');

begin
BranchFetch <= '1'
when  CU_JMP = '1' or (CU_JZ = '1' and Flags(0) = '1') or  (CU_FUNC = '1') 
	      or (IFID_IR(31 downto 27) = "11011")   or (IFID_IR(31 downto 27) = "11100")
	      or (IDEX_IR_OPCODE_OUT = "11011")   or (IDEX_IR_OPCODE_OUT = "11100")
	      or (EXMEM_OPCODE_OUT = "11011")  	      or (EXMEM_OPCODE_OUT = "11100") 
else '0';
IS_RET <= '1' 
when MEMWB_OPCODE_OUT = "11011" or MEMWB_OPCODE_OUT ="11100"
else '0';

IS_RTI <= '1' 
when  MEMSTAGE_OPCODE_OUT ="11100"
else '0';

---------------------Flags---------------------------------
-------------------------------------------------------------
flagsInputLabel :  Mux21Ent generic map (n => 3)  port map(IS_RTI,ExecuteStageFlags,MemOutMemory(31 downto 29),FlagsInput);
flagsLabel :reg generic map(n => 3)       
        port map(clk,GLOBAL_RESET,'1',FlagsInput,flags);
--------------------------------------------------------------

-- first stage : FETCH STAGE
FETCH_STAGE_INSTANCE : fetch_stage port map(
    initial => GLOBAL_INITAIL,
    Clk  => CLK ,
    reset => GLOBAL_RESET,    
    correct_branch_address => ZERO_LOGIC_16,
    address2 => ZERO_LOGIC_16,
    mux8_output => Mux10OutWB(15 downto 0),
    read_data_1 =>DS_RD_DATA_1_OUT(15 downto 0),
    predicted_branch_address => ZERO_LOGIC_16,
    miss_prediction => '0',
    int_fsm => MAIN_INTERRUPT,
    func =>IS_RET,
    branch => BranchFetch,
    branch_prediction => '0',
    stalling            => Hazard_Detection_Stall,
    hold_to_complete_out => STALL_TO_FECTH_COMPELETE, ---should be handled to wait for another fetch  
    out_IR =>FS_IR ,
    out_PC => FS_PC
);
--FIRST BUFFER: IF/ID BUFFER 
FETCH_BUFFER_INSTANCE : fetch_buffer port map (
    clk  => CLK ,
	reset_global  => GLOBAL_RESET,
    enable_global  =>  Hazard_Detection_IF_ID_WR_EN,
    IR_enable  =>  Hazard_Detection_IF_ID_WR_EN,
    IR_reset  => GLOBAL_RESET,
    IR_in => FS_IR,
    IR_out	 => IFID_IR,
    PC_enable =>   Hazard_Detection_IF_ID_WR_EN,
    PC_reset =>GLOBAL_RESET,
    PC_in => FS_PC,
    PC_out	 => IFID_PC,
    INT_in 	=>MAIN_INTERRUPT,
    INT_out	=> IFID_INTR
);
------------------------------------------------------------------
CONTROL_UNIT_INSTANCE : control_unit port map (
    -- INPUTS 
    IR                  => IFID_IR,
    -- OUTPUTS (CONTROL SIGNALS):
    OUT_SIG             => CU_OUT_SIG,
    IN_SIG              => CU_IN_SIG,
    ALU_OPR             => CU_ALU_OPR,
    ALU_SRC             => CU_ALU_SRC,
    REG_DST             => CU_REG_DST,
    MEM_TO_REG          => CU_MEM_TO_REG,
    FETCH_EN            => CU_FETCH_EN,
    DATA_EN             => CU_DATA_EN,
    ALU_EN              => CU_ALU_EN,
    BR_EN               => CU_BR_EN,
    MEM_WR_EN           => CU_MEM_WR_EN,
    MEM_RD_EN           => CU_MEM_RD_EN,
    SWAP                => CU_SWAP,
    IN_SP               => CU_IN_SP,
    SP_INC_DEC          => CU_SP_INC_DEC,
    EA_IMM_SEL          => CU_EA_IMM_SEL,
    JMP                 => CU_JMP,
    JZ                  => CU_JZ,
    FUNC                => CU_FUNC,
    RTI                 => CU_RTI,
    WB                  => CU_WB,
    FLUSH_JMP           => CU_FLUSH_JMP,
    FLUSH_FUNC          => CU_FLUSH_FUNC,
    FLUSH_JZ            => CU_FLUSH_JZ
    );
------------------------------------------------------------------
DECODE_STAGE_INSTANCE : decode_stage port map (
    -- INPUTS
    ENABLE              => GLOBAL_ENABLE,
    RESET               => GLOBAL_RESET,
    CLK                 => CLK,
    IR                  => IFID_IR,
    EA_IMM_SEL          => CU_EA_IMM_SEL,
    WR_ADDRESS_1        => WB_WR_ADDRESS_1,
    WR_ADDRESS_2        => WB_WR_ADDRESS_2,
    WR_DATA_1           => WB_WR_DATA_1,
    WR_DATA_2           => WB_WR_DATA_2,
    WR_EN_1             => WB_WR_EN_1,
    WR_EN_2             => WB_WR_EN_2,
    SWAP_EN             => CU_SWAP,
    REG_DST             => CU_REG_DST,

    -- OUTPUTS
    RD_DATA_1           => DS_RD_DATA_1_OUT,
    RD_DATA_2           => DS_RD_DATA_2_OUT,
    -- HOLDING IMMEDIATE VALUE OR EXTENDED EFFECTIVE ADDRESS
    EA_IMM_DATA         => EAIMM_MUXOP_DS,
    Rdst_address        => DS_Rdst_address,
    Rsrc1_address       => DS_Rsrc1_address,
    Rsrc2_address       => DS_Rsrc2_address
 --_PUTHERE_
    );
------------------------------------------------------------------
ID_EX_INSTANCE : ID_EX port map (
    -- INPUTS 
    ENABLE              => GLOBAL_ENABLE, 
    RESET               => Hazard_Detection_Stall, 
    CLK                 => CLK,
    STALL_SIG           => STALL_TO_FECTH_COMPELETE,

    -- CONTROL SIGNALS
    PC                  => IFID_PC, 
    Rdst                => DS_RD_DATA_2_OUT,
    Rsrc1               => DS_RD_DATA_1_OUT,
    Rsrc2               => DS_RD_DATA_2_OUT,
    EA_IMM_DATA         => EAIMM_MUXOP_DS, 
    Rdst_address        => DS_Rdst_address, 
    Rsrc1_address       => DS_Rsrc1_address,
    Rsrc2_address       => DS_Rsrc2_address,
    OUT_SIG             => CU_OUT_SIG, 
    IN_SIG              => CU_IN_SIG, 
    ALU_OPR             => CU_ALU_OPR,
    ALU_SRC             => CU_ALU_SRC, 
    REG_DST             => CU_REG_DST, 
    MEM_TO_REG          => CU_MEM_TO_REG,
    FETCH_EN            => CU_FETCH_EN, 
    DATA_EN             => CU_DATA_EN,
    ALU_EN              => CU_ALU_EN, 
    BR_EN               => CU_BR_EN,  
    MEM_WR_EN           => CU_MEM_WR_EN, 
    MEM_RD_EN           => CU_MEM_RD_EN, 
    SWAP                => CU_SWAP,
    IN_SP               => CU_IN_SP,  
    SP_INC_DEC          => CU_SP_INC_DEC, 
    EA_IMM              => CU_EA_IMM_SEL, 
    JMP                 => CU_JMP, 
    JZ                  => CU_JZ,
    FUNC                => CU_FUNC,
    RTI                 => CU_RTI, 
    WB                  => CU_WB, 
    FLUSH_JMP           => CU_FLUSH_JMP,
    FLUSH_FUNC          => CU_FLUSH_FUNC, 
    FLUSH_JZ            => CU_FLUSH_JZ,
    IR_OPCODE           => IFID_IR(31 downto 27),
    INTR 		=> IFID_INTR,
    -- OUTPUTS
    OUT_CONTROL_SIGNALS => IDEX_OUT_CONTROL_SIGNALS,
    PC_OUT              => IDEX_PC_OUT,
    Rdst_OUT            => IDEX_Rdst_OUT, 
    Rsrc1_OUT           => IDEX_Rsrc1_OUT,
    Rsrc2_OUT           => IDEX_Rsrc2_OUT,
    EA_IMM_DATA_OUT     => IDEX_EA_IMM_DATA_OUT,
    Rdst_address_OUT    => IDEX_Rdst_address_OUT,
    Rsrc1_address_OUT   => IDEX_Rsrc1_address_OUT,
    Rsrc2_address_OUT   => IDEX_Rsrc2_address_OUT,
    IR_OPCODE_OUT       => IDEX_IR_OPCODE_OUT
    );

------------------------------------------------------------------

------------------------Hazard detection---------------------------
HAZ_DET: Hazard_Detection_Unit_Entity port map(
        --inputs
        IF_ID_OPCODE => IFID_IR(31 downto 27),
        ID_EX_OPCODE=>  IDEX_IR_OPCODE_OUT,
        EX_MEM_OPCODE =>  EXMEM_OPCODE_OUT,

        IF_ID_Rsrc1=> IFID_IR(26 downto 24),
        IF_ID_Rsrc2=> IFID_IR(23 downto 21),
        IF_ID_Rdst => IFID_IR(20 downto 18),

        ID_EX_Rsrc1=> IDEX_Rsrc1_address_OUT,
        ID_EX_Rsrc2=> IDEX_Rsrc2_address_OUT,
        ID_EX_Rdst => IDEX_Rdst_address_OUT,

        EX_MEM_Rsrc1=> EXMEM_Rsrc1_address_OUT,
        EX_MEM_Rsrc2=> EXMEM_Rsrc2_address_OUT,
        EX_MEM_Rdst => EXMEM_Rdst_address_OUT,
        clk => CLK,
    
        --outputs
        Stall=> Hazard_Detection_Stall,
        IF_ID_Write_Enable => Hazard_Detection_IF_ID_WR_EN
    );

----------------------- Execute Stage ------------------------------
ExecuteStage : Execute_Stage_Entity PORT MAP (
                                    --inputs
                                    IDEX_OUT_CONTROL_SIGNALS,
                                    IDEX_PC_OUT ,
                                    IDEX_Rdst_OUT ,
                                    IDEX_Rsrc1_OUT ,
                                    IDEX_Rsrc2_OUT ,
                                    IDEX_EA_IMM_DATA_OUT ,
                                    IDEX_Rdst_address_OUT ,
                                    IDEX_Rsrc1_address_OUT ,
                                    IDEX_Rsrc2_address_OUT ,
                                    IDEX_IR_OPCODE_OUT,

                                    --EX/MEM Outputs
                                    EXMEM_ALU_RESULT ,
                                    EXMEM_CONTROL_SIGNALS  ,
                                    EXMEM_PC  ,
                                    EXMEM_Rdst  ,
                                    EXMEM_Rsrc2  ,
                                    EXMEM_Rdst_address  ,
                                    EXMEM_Rsrc1_address  ,
                                    EXMEM_Rsrc2_address  ,
                                    EX_MEM_OPCODE,
                                    --forwarded data
                                    EXMEM_ALU_RESULT_OUT ,
                                    Mux10OutWB ,

                                    --forwarding unit selectors
                                    Forwarding_Selectors1 ,
                                    Forwarding_Selectors2 ,

                                    --in port data
                                    In_Port ,
                                    
                                    --flags
				    flags,
                                    ExecuteStageFlags,

                                    --CLK
                                    CLK,

                                    --Enable
                                    '1',

                                    --Reset
                                    GLOBAL_RESET

);
-----------------------------------------------------------------------

----------------------- Execute buffer ------------------------------
EXMEM_LABEL : EX_Buffer_Entity PORT MAP (
                                    --Execute stage outputs
                                    EXMEM_ALU_RESULT ,
                                    EXMEM_CONTROL_SIGNALS ,
                                    EXMEM_PC  ,
                                    EXMEM_Rdst  ,
                                    EXMEM_Rsrc2  ,
                                    EXMEM_Rdst_address  ,
                                    EXMEM_Rsrc1_address ,
                                    EXMEM_Rsrc2_address ,
                                    EX_MEM_OPCODE,
                                    --Buffer outputs
                                    EXMEM_ALU_RESULT_OUT,
                                    EXMEM_CONTROL_SIGNALS_OUT ,
                                    EXMEM_PC_OUT ,  
                                    EXMEM_Rdst_OUT ,
                                    EXMEM_Rsrc2_OUT ,
                                    EXMEM_Rdst_address_OUT ,
                                    EXMEM_Rsrc1_address_OUT ,
                                    EXMEM_Rsrc2_address_OUT ,
                                    EXMEM_OPCODE_OUT,
                                    --Write enable
                                    '1',

                                    --CLK
                                    CLK,
                                    GLOBAL_RESET



);
-----------------------------------------------------------------------

----------------------- Memory Stage ------------------------------
MemoryStage : MemoryEnt PORT MAP(
                                    -- Inputs
                                    CLK, 
                                    '1', -- ENABLE 

                                    -- -- Data to test my work
                                    -- ControlSignalSignal, -- CONTROL SIGNAL 
                                    -- '0',    -- Int
                                    -- '0',    -- call
                                    -- "00000000000000000000000000000001", -- PC
                                    -- SPSofyan, -- SP
                                    -- "00000000000000000000000000001000", -- ALU RESULT

                                    -- "00000000000000000000000000001000", -- RDes 
                                    -- "00000000000000000000000000000110", -- RSrc2 (don't use)

                                    -- "101", -- RDesAddress 
                                    -- "010", -- RSrc1Address
                                    -- "100", -- RSrc2Address

                                    -- "00000000000000000000000000001000", -- DATA READ 2

                                    -- Data from nassar
                                    EXMEM_CONTROL_SIGNALS_OUT,
                                    '0',
                                    EXMEM_CONTROL_SIGNALS_OUT(21),
                                    EXMEM_PC_OUT,
                                    SPSofyan,
                                    EXMEM_ALU_RESULT_OUT,

                                    EXMEM_Rdst_OUT ,
                                    EXMEM_Rsrc2_OUT ,

                                    EXMEM_Rdst_address_OUT ,
                                    EXMEM_Rsrc1_address_OUT ,
                                    EXMEM_Rsrc2_address_OUT ,

                                    EXMEM_Rsrc2_OUT,
                                    EXMEM_OPCODE_OUT,
                                    
                                    -- Outputs
                                    RDesDataOutMemory,
                                    RSrc2DataOutMemory,

                                    RDesOutMemory,
                                    RSrcOut1Memory,
                                    RSrcOut2Memory,

                                    MemOutMemory,
                                    SPOutMemory,
                                    ALUResultOutMemory,
                                    ControlSignalsOutMemory,
                                    MEMSTAGE_OPCODE_OUT
                                ); 

----------------------- Memory Buffer ------------------------------
MemoryBuffer : MemBufferEnt PORT MAP(   
                                        -- Inputs
                                        CLK,
                                        GLOBAL_RESET,
                                        '1',
                                        ControlSignalsOutMemory,
                                        SPOutMemory,
                                        MemOutMemory,
                                        ALUResultOutMemory,

                                        RDesDataOutMemory,
                                        RSrc2DataOutMemory,

                                        RDesOutMemory,
                                        RSrcOut1Memory,
                                        RSrcOut2Memory,
                                        MEMSTAGE_OPCODE_OUT,
                                        -- Outputs
                                        RDesDataOutBuffer,
                                        RSrc2DataOutBuffer,

                                        RDesOutBuffer,
                                        RSrcOut1Buffer,
                                        RSrcOut2Buffer,

                                        ControlSignalsOutBuffer,
                                        SPOutBuffer,
                                        MemOutBuffer,
                                        ALUResultOutBuffer,
                                        MEMWB_OPCODE_OUT
);
--------------------------- WB Stage --------------------------------
WBStage : WBEnt PORT MAP(
                            -- Inputs
                            CLK,
                            '1',    -- ENABLE
                            ControlSignalsOutBuffer,    -- CONTROL SIGNAL
                            '0',    -- INT
                            SPOutBuffer,
                            MemOutBuffer,
                            ALUResultOutBuffer,

                            RDesDataOutBuffer,
                            RSrc2DataOutBuffer,

                            RDesOutBuffer,
                            RSrcOut1Buffer,
                            RSrcOut2Buffer,

                            -- Outputs

                            RDesDataOutWB,
                            RSrc2DataOutWB,

                            RDesOutWB,
                            RSrcOut1WB,
                            RSrcOut2WB,

                            ControlSignalsOutWB,
                            IntOutWB,
                            Mux10OutWB,
                            SPOutWB
                            -- WB_WR_EN_1
);

------------------------------ Tri State -------------------------------

TriState1 : TriStateEnt PORT MAP(ControlSignalsOutWB(0),Mux10OutWB,OUTPORT);
-- TriState2 : TriStateSPEnt PORT MAP(SPSignal,SPOutWB,SPSofyan);

--------------------------------Forwarding Unit---------------------------
ForwardingUniy: Forwarding_Unit_Entity PORT MAP(
EXMEM_Rdst_address_OUT,
RDesOutBuffer,
EXMEM_Rsrc1_address,
EXMEM_Rsrc2_address,

EXMEM_OPCODE_OUT,
MEMWB_OPCODE_OUT,
IDEX_IR_OPCODE_OUT,

Forwarding_Selectors1,
Forwarding_Selectors2 );
---------------------------- WB output's logic --------------------------

-- WB
WB_WR_EN_2      <= ControlSignalsOutWB(10);
WB_WR_ADDRESS_2 <= RDesOutWB;
WB_WR_DATA_2    <= Mux10OutWB;

WB_WR_EN_1      <= ControlSignalsOutWB(15);
WB_WR_ADDRESS_1 <= RSrcOut1WB;
WB_WR_DATA_1    <= RDesDataOutWB;

WB_SWAP_EN <= ControlSignalsOutWB(15);
SPSignal <= ControlSignalsOutWB(16) OR IntOutWB;

SPSofyan <= SPOutWB when SPSignal = '1';

end architecture;