fibonacci tested rc1, 107 cycles, 1k2le, 57MHz

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

diff --git a/cpu/src/decoder_b.vhd b/cpu/src/decoder_b.vhd
index 01c11f07b82393499d2f094f7677825b52158672..911bd00678565ed0afc46de313a369fb8d92ef33 100644 (file)
--- a/cpu/src/decoder_b.vhd
+++ b/cpu/src/decoder_b.vhd
@@ -217,10 +217,15 @@ begin
                instr_s.reg_src1_addr := instruction(18 downto 15);
                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.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);
@@ -275,6 +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