signal wb_reg, wb_reg_nxt : writeback_rec;
signal ext_uart,ext_timer,ext_gpmp,ext_7seg : extmod_rec;
+signal ext_uart_out, ext_timer_out, ext_gpmp_out : gp_register_t;
-signal sel_nxt, dmem_we, bus_rx :std_logic;
+signal sel_nxt, dmem_we, bus_rx, ext_anysel : std_logic;
signal calc_mem_res : gp_register_t;
begin
+ ext_timer_out <= (others => '0'); --TODO: delete when timer is connected
+ ext_gpmp_out <= (others => '0'); --TODO: delete when gpm is connected
data_ram : r_w_ram
generic map (
clk ,
reset,
ext_uart,
- data_ram_read_ext,
+ ext_uart_out,
bus_rx,
bus_tx
);
wb_reg.hword <= '0';
wb_reg.byte_s <= '0';
bus_rx <= '1';
+
+ wb_reg.byte_en <= (others => '0');
+ wb_reg.data <= (others =>'0');
elsif rising_edge(clk) then
wb_reg <= wb_reg_nxt;
bus_rx <= '1';
-shift_input: process(data_ram_read, address, dmem_en, dmem_write_en, hword, wb_reg, result, byte_s, alu_jmp, br_pred, write_en)
-
+shift_input: process(data_ram_read, address, dmem_en, dmem_write_en, hword, wb_reg, result, byte_s, alu_jmp, br_pred, write_en, ram_data)
+variable byte_en : byte_en_t;
begin
wb_reg_nxt.address <= address;
wb_reg_nxt.dmem_en <= dmem_en;
wb_reg_nxt.byte_s <= byte_s;
calc_mem_res <= result; --(others => '0');
-
- if (wb_reg.dmem_en = '1' and wb_reg.dmem_write_en = '0') then -- ram read operation --alu_jmp = '0' and
- calc_mem_res <= data_ram_read;
- if (wb_reg.hword = '1') then
- calc_mem_res <= (others => '0');
- if (wb_reg.address(1) = '1') then
- calc_mem_res(15 downto 0) <= data_ram_read(31 downto 16);
- else
- calc_mem_res(15 downto 0) <= data_ram_read(15 downto 0);
- end if;
- end if;
- if (wb_reg.byte_s = '1') then
- calc_mem_res <= (others => '0');
- case wb_reg.address(1 downto 0) is
- when "00" => calc_mem_res(7 downto 0) <= data_ram_read(7 downto 0);
- when "01" => calc_mem_res(7 downto 0) <= data_ram_read(15 downto 8);
- when "10" => calc_mem_res(7 downto 0) <= data_ram_read(23 downto 16);
- when "11" => calc_mem_res(7 downto 0) <= data_ram_read(31 downto 24);
- when others => null;
+
+ wb_reg_nxt.data <= ram_data;
+ byte_en := (others => '0');
+ if dmem_en = '1' then
+ if hword = '1' then
+ case address(BYTEADDR-1 downto 0) is
+ when "00" => byte_en(1 downto 0) := "11";
+ when "10" => byte_en(3 downto 2) := "11";
+ when others => null;
end case;
- end if;
+ elsif byte_s = '1' then
+ case address(BYTEADDR-1 downto 0) is
+ when "00" => byte_en(0) := '1';
+ when "01" => byte_en(1) := '1';
+ when "10" => byte_en(2) := '1';
+ when "11" => byte_en(3) := '1';
+ when others => null;
+ end case;
+ else
+ byte_en := (others => '1');
+ end if;
end if;
+ wb_reg_nxt.byte_en <= byte_en;
+
+ -- if (wb_reg.dmem_en = '1' and wb_reg.dmem_write_en = '0') then -- ram read operation --alu_jmp = '0' and
+ -- calc_mem_res <= data_ram_read;
+ -- if (wb_reg.hword = '1') then
+ -- calc_mem_res <= (others => '0');
+ -- if (wb_reg.address(1) = '1') then
+ -- calc_mem_res(15 downto 0) <= data_ram_read(31 downto 16);
+ -- else
+ -- calc_mem_res(15 downto 0) <= data_ram_read(15 downto 0);
+ -- end if;
+ -- end if;
+ -- if (wb_reg.byte_s = '1') then
+ -- calc_mem_res <= (others => '0');
+ -- case wb_reg.address(1 downto 0) is
+ -- when "00" => calc_mem_res(7 downto 0) <= data_ram_read(7 downto 0);
+ -- when "01" => calc_mem_res(7 downto 0) <= data_ram_read(15 downto 8);
+ -- when "10" => calc_mem_res(7 downto 0) <= data_ram_read(23 downto 16);
+ -- when "11" => calc_mem_res(7 downto 0) <= data_ram_read(31 downto 24);
+ -- when others => null;
+ -- end case;
+ -- end if;
+ -- end if;
--jump <= (alu_jmp xor br_pred) and (write_en or wb_reg.dmem_en);
jump <= (alu_jmp xor br_pred);-- and (write_en or wb_reg.dmem_en);
-- if ((alu_jmp and wb_reg.dmem_en) = '1') then
-- jump_addr <= data_ram_read;
--- end if;
+-- end if;
end process;
-out_logic: process(write_en, result_addr, wb_reg, alu_jmp, wb_reg_nxt, data_ram_read_ext, calc_mem_res)
-
-begin
- reg_we <= (write_en or (wb_reg.dmem_en and not(wb_reg.dmem_write_en))) and not(alu_jmp);
+out_logic: process(write_en, result_addr, wb_reg, alu_jmp, wb_reg_nxt, data_ram_read_ext, calc_mem_res, data_ram_read, ext_anysel)
+variable reg_we_v : std_logic;
+variable data_out : gp_register_t;
+begin
+ reg_we_v := (write_en or (wb_reg.dmem_en and not(wb_reg.dmem_write_en))) and not(alu_jmp);
reg_addr <= result_addr;
data_addr <= (others => '0');
dmem_we <= '0';
+ if (wb_reg.address(DATA_ADDR_WIDTH+2) /= '1') then
+ data_out := data_ram_read;
+ else
+ reg_we_v := reg_we_v and ext_anysel;
+ data_out := data_ram_read_ext;
+ end if;
+
+ if wb_reg.byte_en(0) = '0' then
+ data_out(byte_t'range) := (others => '0');
+ end if;
+ if wb_reg.byte_en(1) = '0' then
+ data_out(2*byte_t'length-1 downto byte_t'length) := (others => '0');
+ end if;
+ if wb_reg.byte_en(2) = '0' then
+ data_out(3*byte_t'length-1 downto 2*byte_t'length) := (others => '0');
+ end if;
+ if wb_reg.byte_en(3) = '0' then
+ data_out(4*byte_t'length-1 downto 3*byte_t'length) := (others => '0');
+ end if;
+
+ data_out := to_stdlogicvector(to_bitvector(data_out) srl to_integer(unsigned(wb_reg.address(BYTEADDR-1 downto 0))));
+
if (wb_reg_nxt.address(DATA_ADDR_WIDTH+2) /= '1') then
data_addr(DATA_ADDR_WIDTH+1 downto 0) <= wb_reg_nxt.address(DATA_ADDR_WIDTH+1 downto 0);
dmem_we <= wb_reg_nxt.dmem_write_en;
end if;
- regfile_val <= calc_mem_res;
-
- if (wb_reg.address(31 downto 4) = EXT_UART_ADDR) then
- regfile_val <= data_ram_read_ext;
- end if;
+ regfile_val <= data_out;
+
+ reg_we <= reg_we_v;
+
end process;
-addr_de_mult: process(wb_reg_nxt, ram_data, wb_reg,sel_nxt)
-
+addr_de_mult: process(wb_reg, wb_reg_nxt, ram_data, sel_nxt, ext_uart_out, ext_gpmp_out, ext_timer_out)
+variable wr_en, enable : std_logic; -- these are all registered
+variable byte_en : byte_en_t; -- if a module needs the nxt signals it has to manually select them
+variable addr : ext_addr_t; -- for example the data memory, because it already has input registers
+variable addrid : ext_addrid_t;
+variable data : gp_register_t;
begin
- ext_uart.sel <='0';
- ext_uart.wr_en <= wb_reg_nxt.dmem_write_en;
- ext_uart.byte_en <= (others => '0');
- ext_uart.data <= (others => '0');
- ext_uart.addr <= (others => '0');
+ --if selecting enable is too slow, see alu_b
+ enable := wb_reg.dmem_en;
+ wr_en := wb_reg.dmem_write_en;
+ byte_en := wb_reg.byte_en;
+ addr := wb_reg.address(gp_register_t'high downto BYTEADDR);
+ addrid := wb_reg.address(gp_register_t'high downto EXTWORDS);
+ data := wb_reg.data;
+ ext_uart.sel <='0';
ext_7seg.sel <='0';
- ext_7seg.wr_en <= wb_reg_nxt.dmem_write_en;
- ext_7seg.byte_en <= (others => '0');
- ext_7seg.data <= (others => '0');
- ext_7seg.addr <= (others => '0');
-
ext_timer.sel <='0';
- ext_timer.wr_en <= wb_reg_nxt.dmem_write_en;
- ext_timer.byte_en <= (others => '0');
- ext_timer.data <= (others => '0');
- ext_timer.addr <= (others => '0');
-
ext_gpmp.sel <='0';
- ext_gpmp.wr_en <= wb_reg_nxt.dmem_write_en;
- ext_gpmp.byte_en <= (others => '0');
- ext_gpmp.data <= (others => '0');
- ext_gpmp.addr <= (others => '0');
+
+ ext_uart.wr_en <= wr_en;
+ ext_7seg.wr_en <= wr_en;
+ ext_timer.wr_en <= wr_en;
+ ext_gpmp.wr_en <= wr_en;
+
+ ext_uart.byte_en <= byte_en;
+ ext_7seg.byte_en <= byte_en;
+ ext_timer.byte_en <= byte_en;
+ ext_gpmp.byte_en <= byte_en;
+
+ ext_uart.addr <= addr;
+ ext_7seg.addr <= addr;
+ ext_timer.addr <= addr;
+ ext_gpmp.addr <= addr;
+
+ ext_uart.data <= data;
+ ext_7seg.data <= data;
+ ext_timer.data <= data;
+ ext_gpmp.data <= data;
-- wenn ich hier statt dem 4rer die konstante nehme dann gibts an fehler wegen nicht lokaler variable -.-
- case wb_reg_nxt.address(31 downto 4) is
--- when EXT_UART_ADDR =>
--- ext_uart.sel <='1';
+ case addrid is
+ when EXT_UART_ADDR =>
+ ext_uart.sel <= enable;
+ ext_anysel <= enable;
-- ext_uart.wr_en <= wb_reg_nxt.dmem_write_en;
-- ext_uart.data <= ram_data;
-- ext_uart.addr <= wb_reg_nxt.address(31 downto 2);
-- end case;
when EXT_7SEG_ADDR =>
- ext_7seg.sel <='1';
- ext_7seg.wr_en <= wb_reg_nxt.dmem_write_en;
- ext_7seg.data <= ram_data;
- ext_7seg.addr <= wb_reg_nxt.address(31 downto 2);
- ext_7seg.byte_en(1 downto 0) <= wb_reg_nxt.address(1 downto 0);
+ ext_7seg.sel <= enable;
+ ext_anysel <= enable;
+ -- ext_7seg.wr_en <= wb_regdmem_write_en;
+ -- ext_7seg.data <= ram_data;
+ -- ext_7seg.addr <= wb_reg_nxt.address(31 downto 2);
+ -- ext_7seg.byte_en(1 downto 0) <= wb_reg_nxt.address(1 downto 0);
-- case wb_reg_nxt.address(1 downto 0) is
-- end case;
when EXT_TIMER_ADDR =>
- ext_timer.sel <='1';
- ext_timer.wr_en <= wb_reg_nxt.dmem_write_en;
- ext_timer.data <= ram_data;
- ext_timer.addr <= wb_reg_nxt.address(wb_reg_nxt.address'high downto BYTEADDR);
- case wb_reg.address(1 downto 0) is
- when "00" => ext_timer.byte_en <= "0001";
- when "01" => ext_timer.byte_en <= "0010";
- when "10" => ext_timer.byte_en <= "0100";
- when "11" => ext_timer.byte_en <= "1000";
- when others => null;
- end case;
+ ext_timer.sel <= enable;
+ ext_anysel <= enable;
+ -- ext_timer.wr_en <= wb_reg_nxt.dmem_write_en;
+ -- ext_timer.data <= ram_data;
+ -- ext_timer.addr <= wb_reg_nxt.address(wb_reg_nxt.address'high downto BYTEADDR);
+ -- case wb_reg.address(1 downto 0) is
+ -- when "00" => ext_timer.byte_en <= "0001";
+ -- when "01" => ext_timer.byte_en <= "0010";
+ -- when "10" => ext_timer.byte_en <= "0100";
+ -- when "11" => ext_timer.byte_en <= "1000";
+ -- when others => null;
+ -- end case;
when EXT_GPMP_ADDR =>
- ext_gpmp.sel <='1';
- ext_gpmp.wr_en <= wb_reg_nxt.dmem_write_en;
- ext_gpmp.data <= ram_data;
- ext_gpmp.addr <= wb_reg_nxt.address(wb_reg_nxt.address'high downto BYTEADDR);
- case wb_reg.address(1 downto 0) is
- when "00" => ext_gpmp.byte_en <= "0001";
- when "01" => ext_gpmp.byte_en <= "0010";
- when "10" => ext_gpmp.byte_en <= "0100";
- when "11" => ext_gpmp.byte_en <= "1000";
- when others => null;
- end case;
+ ext_gpmp.sel <= enable;
+ ext_anysel <= enable;
+ -- ext_gpmp.wr_en <= wb_reg_nxt.dmem_write_en;
+ -- ext_gpmp.data <= ram_data;
+ -- ext_gpmp.addr <= wb_reg_nxt.address(wb_reg_nxt.address'high downto BYTEADDR);
+ -- case wb_reg.address(1 downto 0) is
+ -- when "00" => ext_gpmp.byte_en <= "0001";
+ -- when "01" => ext_gpmp.byte_en <= "0010";
+ -- when "10" => ext_gpmp.byte_en <= "0100";
+ -- when "11" => ext_gpmp.byte_en <= "1000";
+ -- when others => null;
+ -- end case;
-- hier kann man weiter extensions adden :) Konstanten sind im extension pkg definiert
- when others => null;
- end case;
-
+ when others => ext_anysel <= '0';
+ end case;
+
+ data_ram_read_ext <= ext_uart_out or ext_gpmp_out or ext_timer_out;
end process;
end behav;