284 lines
11 KiB
VHDL
284 lines
11 KiB
VHDL
library ieee;
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use ieee.math_real.all;
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use ieee.numeric_std.all;
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use ieee.std_logic_1164.all;
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entity Shifter is
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port(
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shift_lsl : in Std_Logic;
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shift_lsr : in Std_Logic;
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shift_asr : in Std_Logic;
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shift_ror : in Std_Logic; -- rotation sans extension
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shift_rrx : in Std_Logic; -- avec extension
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shift_val : in Std_Logic_Vector(4 downto 0);
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din : in Std_Logic_Vector(31 downto 0);
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cin : in Std_Logic;
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dout : out Std_Logic_Vector(31 downto 0);
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cout : out Std_Logic;
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-- global interface
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vdd : in bit;
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vss : in bit );
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end Shifter;
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-- TODO:
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-- changer les "000" et "temp_dout(31)& temp_dout(31)& ..." par la synthaxe
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-- (n1 downto n0 => '0') ou (n1 downto n0 => '0')
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architecture Shifter_bhvr of Shifter is
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begin
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process(shift_lsl, shift_lsr, shift_asr, shift_ror, shift_rrx,shift_val,
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din, cin, vdd, vss)
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variable temp_dout : Std_Logic_Vector(31 downto 0);
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variable temp_cout : Std_Logic;
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begin
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temp_dout := din;
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temp_cout := cin;
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-- LSL -------------------------------------------------------------
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-- 1
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if(shift_lsl='1' and shift_val(0)='1')
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then
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temp_cout := temp_dout(31);
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temp_dout := (temp_dout(30 downto 0)&'0');
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else NULL;
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end if;
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-- 2
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if(shift_lsl='1' and shift_val(1)='1')
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then
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temp_cout := temp_dout(30);
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temp_dout := (temp_dout(29 downto 0)&"00");
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else NULL;
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end if;
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-- 4
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if(shift_lsl='1' and shift_val(2)='1')
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then
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temp_cout := temp_dout(28);
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temp_dout := (temp_dout(27 downto 0)&"0000");
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else NULL;
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end if;
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-- 8
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if(shift_lsl='1' and shift_val(3)='1')
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then
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temp_cout := temp_dout(24);
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temp_dout :=(temp_dout(23 downto 0)&"00000000");
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else NULL;
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end if;
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-- 16
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if(shift_lsl='1' and shift_val(4)='1')
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then
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temp_cout := temp_dout(16);
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temp_dout :=
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(temp_dout(15 downto 0)&"0000000000000000");
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else NULL;
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end if;
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-- LSR -------------------------------------------------------------
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-- 1
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if(shift_lsr='1' and shift_val(0)='1')
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then
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temp_cout := temp_dout(0);
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temp_dout := ('0'&temp_dout(31 downto 1));
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else NULL;
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end if;
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-- 2
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if(shift_lsr='1' and shift_val(1)='1')
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then
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temp_cout := temp_dout(0);
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temp_dout := ("00"&temp_dout(31 downto 2));
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else NULL;
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end if;
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-- 4
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if(shift_lsr='1' and shift_val(2)='1')
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then
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temp_cout := temp_dout(0);
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temp_dout := ("0000"&temp_dout(31 downto 4));
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else NULL;
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end if;
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-- 8
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if(shift_lsr='1' and shift_val(3)='1')
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then
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temp_cout := temp_dout(0);
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temp_dout :=("00000000"&temp_dout(31 downto 8));
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else NULL;
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end if;
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-- 16
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if(shift_lsr='1' and shift_val(4)='1')
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then
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temp_cout := temp_dout(0);
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temp_dout :=
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("0000000000000000"&temp_dout(31 downto 16));
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else NULL;
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end if;
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-- ASR -------------------------------------------------------------
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-- 1
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if(shift_asr='1' and shift_val(0)='1')
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then
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temp_cout := temp_dout(0);
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temp_dout := (temp_dout(31)
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&temp_dout(31 downto 1));
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else NULL;
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end if;
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-- 2
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if(shift_asr='1' and shift_val(1)='1')
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then
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temp_cout := temp_dout(0);
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temp_dout :=
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( temp_dout(31)& temp_dout(31)
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&temp_dout(31 downto 2));
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else NULL;
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end if;
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-- 4
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if(shift_asr='1' and shift_val(2)='1')
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then
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temp_cout := temp_dout(0);
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temp_dout :=
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( temp_dout(31)& temp_dout(31)
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&temp_dout(31)& temp_dout(31)
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&temp_dout(27 downto 0));
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else NULL;
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end if;
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-- 8
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if(shift_asr='1' and shift_val(3)='1')
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then
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temp_cout := temp_dout(0);
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temp_dout :=
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( temp_dout(31)&temp_dout(31)&temp_dout(31)
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&temp_dout(31)&temp_dout(31)&temp_dout(31)
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&temp_dout(31)&temp_dout(31)
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&temp_dout(23 downto 0));
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else NULL;
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end if;
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-- 16
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if(shift_asr='1' and shift_val(4)='1')
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then
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temp_cout := temp_dout(0);
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temp_dout :=
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( temp_dout(31)& temp_dout(31)&
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temp_dout(31)& temp_dout(31)&
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temp_dout(31)& temp_dout(31)&
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temp_dout(31)& temp_dout(31)&
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temp_dout(31)& temp_dout(31)&
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temp_dout(31)& temp_dout(31)&
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temp_dout(31)& temp_dout(31)&
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temp_dout(31)& temp_dout(31)&
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temp_dout(15 downto 0));
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else NULL;
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end if;
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-- ROR -------------------------------------------------------------
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-- 1
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if(shift_ror='1' and shift_val(0)='1')
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then temp_dout := (temp_dout(0)
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&temp_dout(31 downto 1));
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temp_cout := temp_dout(0);
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else NULL;
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end if;
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-- 2
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if(shift_ror='1' and shift_val(1)='1')
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then temp_dout :=
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(temp_dout(1 downto 0)
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&temp_dout(31 downto 2));
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temp_cout := temp_dout(1);
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else NULL;
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end if;
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-- 4
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if(shift_ror='1' and shift_val(2)='1')
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then temp_dout :=
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(temp_dout(3 downto 0)
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&temp_dout(31 downto 4));
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temp_cout := temp_dout(3);
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else NULL;
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end if;
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-- 8
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if(shift_ror='1' and shift_val(3)='1')
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then temp_dout :=
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(temp_dout(7 downto 0)
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&temp_dout(31 downto 8));
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temp_cout := temp_dout(7);
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else NULL;
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end if;
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-- 16
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if(shift_ror='1' and shift_val(4)='1')
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then temp_dout :=
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(temp_dout(15 downto 0)
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&temp_dout(31 downto 16));
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temp_cout := temp_dout(15);
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else NULL;
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end if;
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-- RRX -------------------------------------------------------------
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-- 1
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if(shift_rrx='1' and shift_val(0)='1')
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then temp_dout := (temp_cout
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&temp_dout(31 downto 1));
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temp_cout := temp_dout(0);
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else NULL;
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end if;
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-- 2
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if(shift_rrx='1' and shift_val(1)='1')
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then temp_dout :=
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(temp_cout
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&temp_dout(0)
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&temp_dout(31 downto 2));
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temp_cout := temp_dout(1);
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else NULL;
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end if;
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-- 4
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if(shift_rrx='1' and shift_val(2)='1')
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then temp_dout :=
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(temp_cout
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&temp_dout(2 downto 0)
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&temp_dout(31 downto 4));
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temp_cout := temp_dout(3);
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else NULL;
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end if;
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-- 8
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if(shift_rrx='1' and shift_val(3)='1')
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then temp_dout :=
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(temp_cout
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&temp_dout(6 downto 0)
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&temp_dout(31 downto 8));
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temp_cout := temp_dout(7);
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else NULL;
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end if;
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-- 16
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if(shift_rrx='1' and shift_val(4)='1')
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then temp_dout :=
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(temp_cout
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&temp_dout(14 downto 0)
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&temp_dout(31 downto 16));
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temp_cout := temp_dout(15);
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else NULL;
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end if;
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cout <= temp_cout;
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dout <= temp_dout;
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end process;
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end Shifter_bhvr;
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