2 use IEEE.std_logic_1164.all;
3 use IEEE.numeric_std.all;
5 use work.common_pkg.all;
9 use work.extension_pkg.all;
11 architecture behav of writeback_stage is
13 signal data_ram_read : word_t;
15 signal wb_reg, wb_reg_nxt : writeback_rec;
17 signal ext_uart,ext_timer,ext_gpmp : extmod_rec;
32 wb_reg_nxt.address(DATA_ADDR_WIDTH+1 downto 2),
33 wb_reg_nxt.address(DATA_ADDR_WIDTH+1 downto 2),
34 wb_reg_nxt.dmem_write_en,
40 syn: process(clk, reset)
44 if (reset = RESET_VALUE) then
45 wb_reg.address <= (others => '0');
46 wb_reg.dmem_en <= '0';
47 wb_reg.dmem_write_en <= '0';
50 elsif rising_edge(clk) then
56 -- type writeback_rec is record
57 -- address : in word_t; --ureg
58 -- dmem_en : in std_logic; --ureg (jump addr in mem or in address)
59 -- dmem_write_en : in std_logic; --ureg
60 -- hword_hl : in std_logic --ureg
65 shift_input: process(data_ram_read, address, dmem_en, dmem_write_en, hword, wb_reg, result, byte_s, alu_jmp, br_pred)
68 wb_reg_nxt.address <= address;
69 wb_reg_nxt.dmem_en <= dmem_en;
70 wb_reg_nxt.dmem_write_en <= dmem_write_en;
71 wb_reg_nxt.hword <= hword;
72 wb_reg_nxt.byte_s <= byte_s;
74 regfile_val <= result; --(others => '0');
76 if (wb_reg.dmem_en = '1' and wb_reg.dmem_write_en = '0') then -- ram read operation --alu_jmp = '0' and
77 regfile_val <= data_ram_read;
78 if (wb_reg.hword = '1') then
79 regfile_val <= (others => '0');
80 if (wb_reg.address(1) = '1') then
81 regfile_val(15 downto 0) <= data_ram_read(31 downto 16);
83 regfile_val(15 downto 0) <= data_ram_read(15 downto 0);
86 if (wb_reg.byte_s = '1') then
87 regfile_val <= (others => '0');
88 case wb_reg.address(1 downto 0) is
89 when "00" => regfile_val(7 downto 0) <= data_ram_read(7 downto 0);
90 when "01" => regfile_val(7 downto 0) <= data_ram_read(15 downto 8);
91 when "10" => regfile_val(7 downto 0) <= data_ram_read(23 downto 16);
92 when "11" => regfile_val(7 downto 0) <= data_ram_read(31 downto 24);
98 jump <= (alu_jmp xor br_pred) and (write_en or wb_reg.dmem_en);
100 if alu_jmp = '0' and br_pred = '1' and write_en = '0' then
105 if ((alu_jmp and wb_reg.dmem_en) = '1') then
106 jump_addr <= data_ram_read;
111 -- result : in gp_register_t; --reg (alu result or jumpaddr)
112 -- result_addr : in gp_addr_t; --reg
113 -- address : in word_t; --ureg
114 -- alu_jmp : in std_logic; --reg
115 -- br_pred : in std_logic; --reg
116 -- write_en : in std_logic; --reg (register file)
117 -- dmem_en : in std_logic; --ureg (jump addr in mem or in result)
118 -- dmem_write_en : in std_logic; --ureg
119 -- hword : in std_logic --ureg
123 out_logic: process(write_en, result_addr, wb_reg, alu_jmp)
126 reg_we <= (write_en or (wb_reg.dmem_en and not(wb_reg.dmem_write_en))) and not(alu_jmp);
127 reg_addr <= result_addr;
131 addr_de_mult: process(wb_reg_nxt.address)
136 ext_uart.wr_en <= '0';
137 ext_uart.byte_en <= (others => '0');
138 ext_uart.data <= (others => '0');
139 ext_uart.addr <= (others => '0');
142 ext_timer.wr_en <= '0';
143 ext_timer.byte_en <= (others => '0');
144 ext_timer.data <= (others => '0');
145 ext_timer.addr <= (others => '0');
148 ext_gpmp.wr_en <= '0';
149 ext_gpmp.byte_en <= (others => '0');
150 ext_gpmp.data <= (others => '0');
151 ext_gpmp.addr <= (others => '0');
152 -- wenn ich hier statt dem 4rer die konstante nehme dann gibts an fehler wegen nicht lokaler variable -.-
153 case wb_reg_nxt.address(wb_reg_nxt.address'high downto 4) is
154 when EXT_UART_ADDR =>
156 ext_uart.wr_en <= wb_reg_nxt.dmem_write_en;
157 ext_uart.data <= ram_data;
158 ext_uart.addr <= wb_reg_nxt.address(wb_reg_nxt.address'high downto BYTEADDR);
159 case wb_reg.address(1 downto 0) is
160 when "00" => ext_uart.byte_en <= "0001";
161 when "01" => ext_uart.byte_en <= "0010";
162 when "10" => ext_uart.byte_en <= "0100";
163 when "11" => ext_uart.byte_en <= "1000";
166 when EXT_TIMER_ADDR =>
168 ext_timer.wr_en <= wb_reg_nxt.dmem_write_en;
169 ext_timer.data <= ram_data;
170 ext_timer.addr <= wb_reg_nxt.address(wb_reg_nxt.address'high downto BYTEADDR);
171 case wb_reg.address(1 downto 0) is
172 when "00" => ext_timer.byte_en <= "0001";
173 when "01" => ext_timer.byte_en <= "0010";
174 when "10" => ext_timer.byte_en <= "0100";
175 when "11" => ext_timer.byte_en <= "1000";
178 when EXT_GPMP_ADDR =>
180 ext_gpmp.wr_en <= wb_reg_nxt.dmem_write_en;
181 ext_gpmp.data <= ram_data;
182 ext_gpmp.addr <= wb_reg_nxt.address(wb_reg_nxt.address'high downto BYTEADDR);
183 case wb_reg.address(1 downto 0) is
184 when "00" => ext_gpmp.byte_en <= "0001";
185 when "01" => ext_gpmp.byte_en <= "0010";
186 when "10" => ext_gpmp.byte_en <= "0100";
187 when "11" => ext_gpmp.byte_en <= "1000";
190 -- hier kann man weiter extensions adden :) Konstanten sind im extension pkg definiert