3 use IEEE.std_logic_1164.all;
4 use IEEE.numeric_std.all;
6 use work.common_pkg.all;
7 use work.extension_pkg.all;
8 --use work.core_extension.all;
13 --type alu_interal_rec is record
15 --end record alu_internal_rec;
17 type alu_result_rec is record
18 result : gp_register_t;
19 result_addr : gp_addr_t;
34 end record alu_result_rec;
36 constant SHIFT_WIDTH : integer := 5; --log2c(gp_register_t'length);
38 constant COND_ZERO : condition_t := "0001";
39 constant COND_NZERO : condition_t := "0000";
40 constant COND_NOFLO : condition_t := "0010";
41 constant COND_OFLO : condition_t := "0011";
42 constant COND_NCARRY : condition_t := "0100";
43 constant COND_CARRY : condition_t := "0101";
44 constant COND_NSIGN : condition_t := "0110";
45 constant COND_SIGN : condition_t := "0111";
47 constant COND_ABOVE : condition_t := "1000";
48 constant COND_BEQ: condition_t := "1001";
49 constant COND_GEQ : condition_t := "1010";
50 constant COND_LT : condition_t := "1011";
51 constant COND_GT : condition_t := "1100";
53 constant COND_LEQ : condition_t := "1101";
54 constant COND_ALWAYS : condition_t := "1110";
55 constant COND_NEVER : condition_t := "1111";
57 function add_oflo(l_neg, r_neg, res_neg : std_logic) return std_logic;
58 -- function addsub_op(left_operand, right_operand : gp_register_t; sub, addc : std_logic; alu_result : alu_result_rec) return alu_result_rec;
60 -- function and_op(left_operand, right_operand : gp_register_t; alu_result : alu_result_rec) return alu_result_rec;
61 -- function or_op(left_operand, right_operand : gp_register_t; alu_result : alu_result_rec) return alu_result_rec;
62 -- function xor_op(left_operand, right_operand : gp_register_t; alu_result : alu_result_rec) return alu_result_rec;
64 -- function shift_op(left_operand, right_operand : gp_register_t; arith,sleft,carry : std_logic ;alu_result : alu_result_rec) return alu_result_rec;
67 --some modules won't need all inputs
74 cond : in condition_t;
75 op_group : in op_info_t;
76 left_operand : in gp_register_t;
77 right_operand : in gp_register_t;
79 displacement : in gp_register_t;
80 prog_cnt : in instr_addr_t;
83 op_detail : in op_opt_t;
85 alu_state : in alu_result_rec;
86 pval : in gp_register_t;
87 pval_nxt : in gp_register_t;
89 alu_result : out alu_result_rec;
90 addr : out word_t; --memaddr
91 data : out gp_register_t; --mem data --ureg
94 pwr_en : out std_logic;
101 package body alu_pkg is
103 function add_oflo(l_neg, r_neg , res_neg: std_logic) return std_logic is
105 return (l_neg AND r_neg AND not(res_neg)) OR
106 (not(l_neg) AND not(r_neg) AND res_neg);
107 end function add_oflo;
109 -- function addsub_op(left_operand, right_operand : gp_register_t; sub, addc : std_logic; alu_result : alu_result_rec) return alu_result_rec is
110 -- variable alu_result_out : alu_result_rec;
111 -- variable complement : gp_register_t;
112 -- variable carry_res : unsigned(gp_register_t'length downto 0);
113 -- variable tmp_right_operand : unsigned(gp_register_t'length downto 0);
114 -- variable oflo1, oflo2, l_neg, r_neg : std_logic;
115 -- variable addcarry : unsigned(carry_res'range);
117 -- alu_result_out := alu_result;
119 -- addcarry := (others =>'0');
120 -- addcarry(0) := unsigned(alu_result.status.carry and addc);
122 -- complement := inc(not(right_operand));
123 -- l_neg := left_operand(gp_register_t'high);
125 -- carry_res := unsigned('0' & left_operand)+addcarry;
126 -- oflo1 := add_oflo(l_neg,'0',std_logic_vector(carry_res)(gp_register_t'high));
129 -- tmp_right_operand := unsigned('0' & complement);
131 -- tmp_right_operand := unsigned('0' & right_operand);
134 -- l_neg := std_logic_vector(carry_res)(gp_register_t'high);
135 -- r_neg := std_logic_vector(tmp_right_operand)(gp_register_t'high);
137 -- carry_res := carry_res + tmp_right_operand;
138 -- oflo2 := add_oflo(l_neg,r_neg,std_logic_vector(carry_res)(gp_register_t'high));
141 -- alu_result_out.result := std_logic_vector(carry_res)(gp_register_t'range);
142 -- alu_result_out.status.carry := std_logic_vector(carry_res)(carry_res'high);
145 -- alu_result_out.status.carry := oflo1 or oflo2;
147 -- --sign will be set globally.
148 -- --zero will be set globally.
150 -- return alu_result_out;
151 -- end function addsub_op;
153 -- function and_op(left_operand, right_operand : gp_register_t; alu_result : alu_result_rec) return alu_result_rec is
154 -- variable alu_result_out : alu_result_rec;
156 -- alu_result_out := alu_result;
157 -- alu_result_out.result := left_operand and right_operand;
158 -- end function and_op;
160 -- function or_op(left_operand, right_operand : gp_register_t; alu_result : alu_result_rec) return alu_result_rec is
161 -- variable alu_result_out : alu_result_rec;
163 -- alu_result_out := alu_result;
164 -- alu_result_out.result := left_operand or right_operand;
165 -- end function or_op;
167 -- function xor_op(left_operand, right_operand : gp_register_t; alu_result : alu_result_rec) return alu_result_rec is
168 -- variable alu_result_out : alu_result_rec;
170 -- alu_result_out := alu_result;
171 -- alu_result_out.result := left_operand xor right_operand;
172 -- end function xor_op;
174 -- function shift_op(left_operand, right_operand : gp_register_t; arith,rs,carry : std_logic ;alu_result : alu_result_rec) return alu_result_rec is
175 -- variable alu_result_out : alu_result_rec;
176 -- variable tmp_shift : bit_vector(gp_register_t'length+1 downto 0);
177 -- variable tmp_sb : std_logic;
179 -- alu_result_out := alu_result;
182 -- tmp_sb := (carry and alu_result.status.carry and not(arith)) or (arith and left_operand(gp_register_t'high));
183 -- tmp_shift := bit_vector(tmp_sb & left_operand & alu_result.status.carry);
184 -- tmp_shift := tmp_shift sra to_integer(unsigned(right_operand)(SHIFT_WIDTH-1 downto 0));
186 -- alu_result_out.status.carry := std_logic_vector(tmp_shift)(0);
188 -- tmp_sb := (carry and alu_result.status.carry and not(arith));
189 -- tmp_shift := bit_vector(alu_result.status.carry & left_operand & tmp_sb);
190 -- tmp_shift := tmp_shift sla to_integer(unsigned(right_operand)(SHIFT_WIDTH-1 downto 0));
192 -- alu_result_out.status.carry := std_logic_vector(tmp_shift)(tmp_shift'high);
195 -- alu_result_out.result := std_logic_vector(tmp_shift)(gp_register_t'length downto 1);
197 -- end function shift_op;
199 end package body alu_pkg;