Remove FSL from Tumbl completely

[fpga/lx-cpu1/tumbl.git] / hw / decode.vhd

diff --git a/hw/decode.vhd b/hw/decode.vhd
index bee212b1bbfda85415f911e6082254aaeb48ae88..c7d9c861adb7259c0ae18dc3a7df8e2aa9fa9fac 100644 (file)
--- a/hw/decode.vhd
+++ b/hw/decode.vhd
@@ -36,7 +36,9 @@ ENTITY decode IS
         ID2EX_o     : OUT ID2EX_Type;
         --
         INT_CTRL_i  :  IN INT_CTRL_Type;
-        ID2CTRL_o   : OUT ID2CTRL_Type
+        ID2CTRL_o   : OUT ID2CTRL_Type;
+                               --
+                               noLiteOpc_o : OUT STD_LOGIC
         );
 END ENTITY decode;
 
@@ -45,8 +47,6 @@ END ENTITY decode;
 ARCHITECTURE rtl OF decode IS
 --------------------------------------------------------------------------------
 
-    SIGNAL noLiteOpc_s : STD_LOGIC;
-
 BEGIN
 
 p_decode:
@@ -59,7 +59,6 @@ p_decode:
         VARIABLE rA_v            : STD_LOGIC_VECTOR ( 4 DOWNTO 0);
         VARIABLE rB_v            : STD_LOGIC_VECTOR ( 4 DOWNTO 0);
         VARIABLE IMM16_v         : STD_LOGIC_VECTOR (15 DOWNTO 0);
-        VARIABLE FSL_Mode_v      : STD_LOGIC_VECTOR ( 4 DOWNTO 0);
         VARIABLE code_x26_v      : STD_LOGIC_VECTOR ( 2 DOWNTO 0);
         VARIABLE IMM_Lock_v      : STD_LOGIC;
         VARIABLE alu_Action_v    : ALU_ACTION_Type;
@@ -91,12 +90,11 @@ p_decode:
         mem_Action_v    := NO_MEM;
         transfer_Size_v := WORD;
         wrb_Action_v    := WRB_EX;
-        FSL_Mode_v      := "01010";
         -- for decoding SEXT16, SEXT8, SRC, SRC or SRL
         code_x26_v      := instruction_v(6) & instruction_v(5) & instruction_v(0);
         int_busy_v      := INT_CTRL_i.int_busy;
         -- for debugging purposes
-        noLiteOpc_s     <= '0';
+        noLiteOpc_o     <= '0';
 
         IF (INT_CTRL_i.setup_int = '1') THEN
 
@@ -149,13 +147,13 @@ p_decode:
                         END IF;
                     END IF;
 
-                WHEN "01" =>                                            -- MUL / BS / FSL
+                WHEN "01" =>                                            -- MUL / BS
                     CASE opcIx_v (2 DOWNTO 0) IS
                         WHEN "000" =>                                   -- MUL
                             IF (USE_HW_MUL_g = TRUE) THEN
                                 alu_Action_v := A_MUL;
                             ELSE
-                                noLiteOpc_s <= '1';
+                                noLiteOpc_o <= '1';
                             END IF;
                         WHEN "001" =>                                   -- BS
                             IF (USE_BARREL_g = TRUE) THEN
@@ -169,24 +167,10 @@ p_decode:
                                     END IF;
                                 END IF;
                             ELSE
-                                noLiteOpc_s <= '1';
-                            END IF;
-                        WHEN "011" =>                                   -- FSL
-                            IF (opcIx_v(3) = '0') THEN
-                                FSL_Mode_v := instruction_v(10 DOWNTO  6);
-                            ELSE
-                                FSL_Mode_v := instruction_v(15 DOWNTO 11);
+                                noLiteOpc_o <= '1';
                             END IF;
-                            IF (FSL_Mode_v(4) = '0') THEN
-                                alu_Action_v := A_FSL_GET;
-                                wrb_Action_v := WRB_FSL;
-                            ELSE
-                                alu_Action_v := A_FSL_PUT;
-                                wrb_Action_v := NO_WRB;
-                            END IF;
-                            msr_Action_v := UPDATE_CARRY;
                         WHEN OTHERS =>
-                            noLiteOpc_s <= '1';
+                            noLiteOpc_o <= '1';
                     END CASE;
 
                 WHEN "10" =>
@@ -201,7 +185,7 @@ p_decode:
                                     WHEN "10" =>                        -- SRL
                                         alu_Cin_v := CIN_ZERO;
                                     WHEN OTHERS =>
-                                        noLiteOpc_s <= '1';
+                                        noLiteOpc_o <= '1';
                                 END CASE;
                                 alu_Action_v := A_SHIFT;
                                 msr_Action_v := UPDATE_CARRY;
@@ -210,7 +194,7 @@ p_decode:
                             WHEN "111" =>                               -- SEXT16
                                 alu_Action_v := A_SEXT16;
                             WHEN OTHERS  =>
-                                noLiteOpc_s  <= '1';
+                                noLiteOpc_o  <= '1';
                         END CASE;
                     ELSIF (opcIx_v (3 DOWNTO 0) = "1100") THEN          -- IMM
                         IMM_Lock_v   := '1';
@@ -225,7 +209,7 @@ p_decode:
 --                          WHEN "10010" =>                             -- RTBD
 --                          WHEN "10100" =>                             -- RTED
                             WHEN OTHERS  =>
-                                noLiteOpc_s <= '1';
+                                noLiteOpc_o <= '1';
                         END CASE;
                         alu_Action_v    := A_ADD;
                         branch_Action_v := BR;
@@ -239,7 +223,7 @@ p_decode:
                                 alu_Action_v := A_MTS;
                                 wrb_Action_v := NO_WRB;
                             WHEN OTHERS  =>
-                                noLiteOpc_s  <= '1';
+                                noLiteOpc_o  <= '1';
                         END CASE;
                         rB_v := (OTHERS => '0');    -- in order to prevent occasional hazards (r16, r24)
                     ELSE
@@ -288,14 +272,14 @@ p_decode:
                                     WHEN "0101" =>                      -- BGE
                                         branch_Action_v := BGE;
                                     WHEN OTHERS =>
-                                        noLiteOpc_s <= '1';
+                                        noLiteOpc_o <= '1';
                                 END CASE;
                                 alu_Action_v := A_ADD;
                                 alu_Op1_v    := ALU_IN_PC;
                                 delayBit_v   := rD_v(4);
                             wrb_Action_v := NO_WRB;     -- evaluate and update/overwrite in exeq
                             WHEN OTHERS =>
-                                noLiteOpc_s  <= '1';
+                                noLiteOpc_o  <= '1';
                         END CASE;
                     END IF;
 
@@ -306,7 +290,7 @@ p_decode:
                         WHEN "01"   => transfer_Size_v := HALFWORD;
                         WHEN "10"   => transfer_Size_v := WORD;
                         WHEN OTHERS =>
-                            noLiteOpc_s <= '1';
+                            noLiteOpc_o <= '1';
                     END CASE;
                     IF (opcIx_v(2) = '0') THEN
                         mem_Action_v := RD_MEM;
@@ -317,7 +301,7 @@ p_decode:
                     END IF;
 
                 WHEN OTHERS =>
-                    noLiteOpc_s  <= '1';
+                    noLiteOpc_o  <= '1';
 
             END CASE;
 
@@ -342,10 +326,6 @@ p_decode:
         ID2EX_o.mem_Action       <= mem_Action_v;
         ID2EX_o.transfer_Size    <= transfer_Size_v;
         ID2EX_o.wrb_Action       <= wrb_Action_v;
-        ID2EX_o.FSL_Non_blocking <= FSL_Mode_v(3);
-        ID2EX_o.FSL_Control      <= FSL_Mode_v(2);
-        ID2EX_o.FSL_Test         <= FSL_Mode_v(1);
-        ID2EX_o.FSL_Atomic       <= FSL_Mode_v(0);
         --
         ID2CTRL_o.delayBit      <= delayBit_v;
         ID2CTRL_o.int_busy      <= int_busy_v;