X-Git-Url: http://wien.tomnetworks.com/gitweb/?a=blobdiff_plain;f=cpu%2Fsrc%2Ffetch_stage_b.vhd;h=c975af29702992b673c6c8fce467f19ba2ceeb20;hb=250b78e68b59bb5639dba5f0f3e2b23cbe71f823;hp=b2058a7a03e2c7daed0efc173dbf966576db58e2;hpb=b333da851dda456b48f2a2535c4aeba143c657e1;p=calu.git

diff --git a/cpu/src/fetch_stage_b.vhd b/cpu/src/fetch_stage_b.vhd
index b2058a7..c975af2 100644
--- a/cpu/src/fetch_stage_b.vhd
+++ b/cpu/src/fetch_stage_b.vhd
@@ -13,11 +13,12 @@ signal instr_r_addr  	 : instruction_addr_t;
 signal instr_r_addr_nxt  : instruction_addr_t;
 signal instr_we      	 : std_logic;
 signal instr_wr_data 	 : instruction_word_t;
-signal instr_rd_data 	 : instruction_word_t;
+signal instr_rd_data_rom, instr_rd_data 	 : instruction_word_t;
+signal rom_ram, rom_ram_nxt : std_logic;
 
 begin
 
-	instruction_ram : rom --r_w_ram
+	instruction_ram : r_w_ram --rom
 		generic map (
 			PHYS_INSTR_ADDR_WIDTH,
 			WORD_WIDTH
@@ -25,12 +26,25 @@ begin
 		
 		port map (
 			clk,
-			instr_w_addr(PHYS_INSTR_ADDR_WIDTH-1 downto 0),
+			im_addr(PHYS_INSTR_ADDR_WIDTH-1 downto 0),
 			instr_r_addr_nxt(PHYS_INSTR_ADDR_WIDTH-1 downto 0),
-			instr_we,
-			instr_wr_data,
+			new_im_data_in,
+			im_data,
 			instr_rd_data
 		);
+		
+	instruction_rom : rom
+		generic map (
+			ROM_INSTR_ADDR_WIDTH,
+			WORD_WIDTH
+		)
+		
+		port map (
+			clk,
+			instr_r_addr_nxt(ROM_INSTR_ADDR_WIDTH-1 downto 0),
+			instr_rd_data_rom
+		);
+		
 
 syn: process(clk, reset)
 
@@ -38,35 +52,82 @@ begin
 
 	if (reset = RESET_VALUE) then
 		instr_r_addr <= (others => '0');
+		rom_ram <= ROM_USE;
+		led2 <= '0';
 	elsif rising_edge(clk) then
 		instr_r_addr <= instr_r_addr_nxt;		
+		rom_ram <= rom_ram_nxt;
+		led2 <= rom_ram; --rom_ram_nxt;
 	end if;
 	
 end process; 
 
 
-asyn: process(reset, instr_r_addr, jump_result, prediction_result, branch_prediction_bit, alu_jump_bit, instr_rd_data)
-
+asyn: process(reset, s_reset, instr_r_addr, jump_result, prediction_result, branch_prediction_bit, alu_jump_bit, instr_rd_data, rom_ram, instr_rd_data_rom, int_req)
+variable instr_pc  : instruction_addr_t;
 begin
-
-	instruction <= instr_rd_data;
-	instr_r_addr_nxt <= std_logic_vector(unsigned(instr_r_addr) + 1);
+	rom_ram_nxt <= rom_ram;
+	
+--	if (s_reset = RESET_VALUE) then
+--		rom_ram_nxt <= RAM_USE;
+--		instr_r_addr_nxt <= (others => '0');
+--	end if;
+	
+	case rom_ram is
+		when ROM_USE =>
+			instruction <= instr_rd_data_rom;
+		when RAM_USE =>
+			instruction <= instr_rd_data;
+		when others => 
+			instruction <= x"F0000000";
+	end case;
+	instr_pc := std_logic_vector(unsigned(instr_r_addr) + 1);
+	instr_r_addr_nxt <= instr_pc;
+
+	if (instr_pc = x"0000007f" and rom_ram = ROM_USE) then
+		rom_ram_nxt <= RAM_USE;
+		-- TODO: wenn genau auf adresse 0 im RAM ein br steht kracht es... :/
+		instr_r_addr_nxt <= x"00000000";
+	end if;
 
 	if (reset = RESET_VALUE) then
 		instr_r_addr_nxt <= (others => '0');
 	end if;
 
-	if (alu_jump_bit = LOGIC_ACT) then
+	if (alu_jump_bit = LOGIC_ACT and int_req = IDLE) then
 		instr_r_addr_nxt <= jump_result;
 		instruction(31 downto 28) <= "1111";	
 	elsif (branch_prediction_bit = LOGIC_ACT) then
 		instr_r_addr_nxt <= prediction_result;
 	end if;	
 
+	case int_req is
+		when UART =>
+			instruction(31 downto 0) <= (others => '0');
+			instruction(31 downto 28) <= "1110";
+			instruction(27 downto 23) <= "10110";
+			instruction(PHYS_INSTR_ADDR_WIDTH + 7 - 1 downto 7) <= UART_INT_VECTOR;
+			instruction(6 downto 4) <= "001";
+			instruction(3 downto 2) <= "01";
+			instruction(1 downto 0) <= "10";
+
+--			instr_r_addr_nxt <= instr_r_addr; 
+		when others => null;
+	end case;
+
 end process;
 
-prog_cnt(10 downto 0) <= std_logic_vector(unsigned(instr_r_addr(PHYS_INSTR_ADDR_WIDTH-1 downto 0)));
-prog_cnt(31 downto 11) <= (others => '0');
+out_logic : process (instr_r_addr, alu_jump_bit, int_req, jump_result)
+
+begin
+	prog_cnt(10 downto 0) <= std_logic_vector(unsigned(instr_r_addr(PHYS_INSTR_ADDR_WIDTH-1 downto 0)));
+	prog_cnt(31 downto 11) <= (others => '0');
+
+	if (int_req /= IDLE and alu_jump_bit = LOGIC_ACT ) then
+		prog_cnt(10 downto 0) <= jump_result(10 downto 0);
+	end if;
+
+end process;
 
 end behav;