2 use IEEE.std_logic_1164.all;
3 use IEEE.numeric_std.all;
5 use work.common_pkg.all;
9 architecture behav of execute_stage is
11 signal condition : condition_t;
12 signal op_group : op_info_t;
13 signal op_detail : op_opt_t;
14 signal left_operand, right_operand : gp_register_t;
15 signal alu_state, alu_nxt : alu_result_rec;
16 signal psw : status_rec;
18 type exec_internal is record
19 result : gp_register_t;
26 signal reg, reg_nxt : exec_internal;
31 port map(clk, reset, condition, op_group,
32 left_operand, right_operand, dec_instr.displacement, op_detail, alu_state, alu_nxt,addr,data);
35 generic map(RESET_VALUE)
36 port map(clk,reset,alu_nxt,psw);
38 syn: process(clk, reset)
42 if reset = RESET_VALUE then
46 reg.result <= (others =>'0');
47 reg.res_addr <= (others => '0');
48 elsif rising_edge(clk) then
54 asyn: process(reset,dec_instr, alu_nxt, psw, reg,left_operand,right_operand)
57 condition <= dec_instr.condition;
58 op_group <= dec_instr.op_group;
59 op_detail <= dec_instr.op_detail;
63 alu_state <= (reg.result,dec_instr.daddr,psw,'0',dec_instr.brpr,'0','0','0','0','0','0');
66 if reset = RESET_VALUE then
67 condition <= COND_NEVER;
72 reg_nxt.brpr <= alu_nxt.brpr;
73 reg_nxt.alu_jump <= alu_nxt.alu_jump;
74 reg_nxt.wr_en <= alu_nxt.reg_op;
75 reg_nxt.result <= alu_nxt.result;
76 reg_nxt.res_addr <= alu_nxt.result_addr;
80 forward: process(regfile_val, reg_we, reg_addr, dec_instr)
82 left_operand <= dec_instr.src1;
83 right_operand <= dec_instr.src2;
86 if dec_instr.saddr1 = reg_addr then
87 left_operand <= regfile_val;
89 if (dec_instr.saddr2 = reg_addr) and (dec_instr.op_detail(IMM_OPT) = '0') then
90 right_operand <= regfile_val;
96 result_addr <= reg.res_addr;
97 alu_jump <= reg.alu_jump;
100 dmem <= alu_nxt.mem_op;
101 --dmem <= reg.result(4);
102 dmem_write_en <= alu_nxt.mem_en;
103 --dmem_write_en <= reg.result(0);
104 --dmem_write_en <= '1';
105 hword <= alu_nxt.hw_op;
106 --hword <= reg.result(1);
107 byte_s <= alu_nxt.byte_op;
109 --addr <= alu_nxt.result;
110 --data <= right_operand;
111 --byte_s <= reg.result(2);