instr mem durch case, fibonacci als programm, 7seg als extension geadded, resultat...

[calu.git] / cpu / src / decoder_b.vhd

diff --git a/cpu/src/decoder_b.vhd b/cpu/src/decoder_b.vhd
index 339d11d1af28ff04ba55bbf8b6cc7667d26f2711..7425381c64162eede4c65b665c5f70338c67e4a7 100644 (file)
--- a/cpu/src/decoder_b.vhd
+++ b/cpu/src/decoder_b.vhd
@@ -154,7 +154,7 @@ begin
                instr_s.op_detail(IMM_OPT) := '1';
                instr_s.op_detail(NO_PSW_OPT) := instruction(0);
 
-               if (instr_s.opcode = "00111") then
+               if (instr_s.opcode = "00101") then
                        instr_s.op_group := AND_OP;
                end if;
 
@@ -215,19 +215,33 @@ begin
 --     when "01110" =>         --ldw
                instr_s.reg_dest_addr := instruction(22 downto 19);
                instr_s.reg_src1_addr := instruction(18 downto 15);
-               instr_s.immediate(15 downto 0) := instruction(18 downto 3);
                instr_s.signext := instruction(2);
                instr_s.high_low := instruction(1);
+               instr_s.displacement(14 downto 0) := instruction(14 downto 0);
 
                instr_s.op_group := LDST_OP;
                instr_s.op_detail(NO_PSW_OPT) := '1';
 
-               if (instr_s.opcode = "11010") then
+               if (instr_s.displacement(14) = '1') then
+                       instr_s.displacement(31 downto 15) := (others => '1');
+               end if;
+
+               if (instr_s.opcode = "11010") then              --ldi
+                       if (instr_s.high_low = '1') then
+                               instr_s.immediate(31 downto 16) := instruction(18 downto 3);
+                               instr_s.immediate(15 downto 0) := (others => '0');
+                       else
+                               instr_s.immediate(15 downto 0) := instruction(18 downto 3);
+                               instr_s.immediate(31 downto 16) := (others => '0');
+
+                               --instr_s.immediate(11 downto 0) := instruction(14 downto 3);
+                               --instr_s.immediate(WORD_WIDTH-1 downto 12) := (others => '0');
+                       end if;                 
+
                        if (instr_s.signext = '1' and instr_s.immediate(11) = '1') then
                                instr_s.immediate(31 downto 16) := (others => '1');
                        end if;
-                       instr_s.immediate(11 downto 0) := instruction(14 downto 3);
-                       instr_s.immediate(WORD_WIDTH-1 downto 12) := (others => '0');
+
                        instr_s.op_detail(IMM_OPT) := '1';
                end if;
        end if;
@@ -266,6 +280,10 @@ begin
                instr_s.op_detail(NO_PSW_OPT) := '1';
                 instr_s.op_detail(ST_OPT) := '1';
                instr_s.op_group := LDST_OP;
+
+               if (instr_s.displacement(14) = '1') then
+                       instr_s.displacement(31 downto 15) := (others => '1');
+               end if;
        end if;
 
 --     when "10001" =>         --sth
@@ -312,7 +330,17 @@ begin
                        instr_s.op_group := JMP_OP;
                end if;
                
-               if (instr_s.predicates = "1111") then
+               if (instr_s.jmptype = "01") then
+                       instr_s.op_group := JMP_ST_OP;
+               --      instr_s.op_detail(RET_OPT) := '0';
+               end if;
+
+               if (instr_s.jmptype = "10") then
+                       instr_s.op_group := JMP_ST_OP;
+                       instr_s.op_detail(RET_OPT) := '1';
+               end if;
+
+               if (instr_s.predicates = "1111" or instr_s.jmptype = "10") then
                        instr_s.bp := '0';
                end if;
        end if;