Floating Point Unit - multiplier block

prepared by P. Bakowski (designer G. Ramstein)

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note : non synthetisable

MULTIPLIER ENTITY

entity Multiplier_Nty is

port(Ck : in Bit; -- Horloge

Hldb : in Bit; -- Hold

Abort : in Bit; -- Abort

RF_MUSD2F : in Bit; -- Multiplier Instructed

RF_T5D2F : in Bit; -- MR register Read/Write

RF_MFOPD2F : in Bit_vector(7 downto 0); -- Code instruction

PS_TRUNC1F : in Bit; -- Mode arrondi 0=Plus pret, 1= Troncature

PS_RND321F : in Bit; -- Format 0/1= 40/32 bits

PS_SRCU1F : in Bit; -- Alternance Foreground/Background

MFX2F, MFY2F : in bit_vector(39 downto 0); -- operandes X et Y

MFR2F : out bit_vector(39 downto 0); -- resultat Stat2F : out bit_vector(1 to 5) --

MN, MI, MV, MU, MF );

end Multiplier_Nty;

-- MULTIPLIER ARCHITECTURE

use WORK.FLOAT40_pkg.all;

use WORK.bitvector_pkg.all;

use WORK.signvector_pkg.all;

architecture Multiplier_a of Multiplier_Nty is

signal Muphi1, Muphi2 : Bit;

begin

process(Ck)

variable Inste : bit_vector(7 downto 0); -- Instruction Pipeline a executer

variable Instructede : Bit; -- Pipeline a executer RF_MUSD2F

variable Transfere : Bit; -- RF_T5D2F

variable Trunc, Rnd32, Srcu : Bit;

variable mrf2, mrf1, mrf0 : bit_vector(31 downto 0); -- Foreground MR2,MR1,MR0, phase 1

variable mrb2, mrb1, mrb0 : bit_vector(31 downto 0); -- Background MR2,MR1,MR0, phase 1

variable temp2, temp1, temp0 : bit_vector(31 downto 0); -- Variables temporaires

variable X, Y, Rs0, Rs1, Rs2 : Fix_Typ;

variable XF, YF, RF : Float_Typ;

variable MN, MI, MV, MU, MF : Bit; -- Negatif, Invalide, Underflow, oVerflow, Flottant

begin

if Ck='1' then

Trunc:=PS_TRUNC1F; Rnd32:=PS_RND321F; Srcu:=PS_SRCU1F; X :=Fix_Typ(MFX2F(39 downto 8)); Y :=Fix_Typ(MFY2F(39 downto 8)); XF:=Float_Typ(MFX2F); YF:=Float_Typ(MFY2F);

if Rnd32='1' then

XF(7 downto 0):=X"00"; YF(7 downto 0):=X"00";

end if;

Inste:=RF_MFOPD2F; Transfere:=RF_T5D2F; Instructede:=RF_MUSD2F;

-- INSTRUCTION DE TRANSFERT

if Abort='0' and Instructede='1' and Transfere='1' then

if Inste(4)='0' then

-------- LECTURE MR -------------------------

MFR2F(7 downto 0)<=X"00"; if (Inste(2) xor Srcu)='0' then

---- FOREGROUND -------

if Inste(1)='0' and Inste(0)='0' then

---- MR0 --------------

MFR2F(39 downto 8) <= mrf0;

end if;

if Inste(1)='0' and Inste(0)='1' then

---- MR1 --------------

MFR2F(39 downto 8) <= mrf1;

end if;

if Inste(1)='1' and Inste(0)='0' then

---- MR2 --------------

MFR2F(39 downto 24) <= (others=> mrf2(15)); -- etendu au signe

MFR2F(23 downto 8) <= mrf2(15 downto 0);

end if;

else

--------------------------------- BACKGROUND -------------

if Inste(1)='0' and Inste(0)='0' then

---- MR0 --------------

MFR2F(39 downto 8) <= mrb0;

end if;

if Inste(1)='0' and Inste(0)='1' then

---- MR1 --------------

MFR2F(39 downto 8) <= mrb1;

end if;

if Inste(1)='1' and Inste(0)='0' then

---- MR2 --------------

MFR2F(39 downto 24) <= (others=> mrb2(15));

-- etendu au signe

MFR2F(23 downto 8) <= mrb2(15 downto 0);

end if;

else

-- ECRITURE MR

if (Inste(2) xor Srcu)='0' then

-- FOREGROUND

if Inste(1)='0' and Inste(0)='0' then

---- MR0

mrf0:=bit_vector(Y);

end if;

if Inste(1)='0' and Inste(0)='1' then

---- MR1 --------------

mrf1:=bit_vector(Y); if Y(31)='1' then

mrf2:=X"0000FFFF";

else mrf2:=X"00000000";

end if;

if Inste(1)='1' and Inste(0)='0' then

---- MR2 --------------

mrf2:=bit_vector(Y) and X"0000FFFF";

end if;

else

--------------------------------- BACKGROUND ---------------

if Inste(1)='0' and Inste(0)='0' then

---- MR0 --------------

mrb0:=bit_vector(Y);

end if;

if Inste(1)='0' and Inste(0)='1' then

---- MR1 --------------

mrb1:=bit_vector(Y);

if Y(31)='1' then

mrb2:=X"0000FFFF";

else mrb2:=X"00000000";

end if;

if Inste(1)='1' and Inste(0)='0' then

---- MR2 --------------

mrb2:=bit_vector(Y) and X"0000FFFF"; end if; end if; end if; end if;

-- Transfert

-- INSTRUCTION DE TYPE CALCUL

if Abort='0' and Instructede='1' and Transfere='0' then

-- INSTRUCTIONS SUR LES REGISTRES MR

if Inste(7)='0' and inste(6)='0' and inste(5)='0' then

------------------ Clear MR ----------------

-- 00 010 xmx ---

if inste(4)='1' and inste(3)='0' then

if (inste(1) xor srcu) ='0' then

-- Foreground 00 010 xX"

mrf2 :=X"00000000"; mrf1 :=X"00000000"; mrf0 :=X"00000000";

else

-- Background 00 010 x1x

mrb2 :=X"00000000"; mrb1 :=X"00000000"; mrb0 :=X"00000000";

end if; MN :='0'; MI :='0'; MV :='0'; MU :='0'; MF :='0';

end if;

-- end Clear ---------------------

-- Saturate MR --------------- 00 00m mmm ----

if inste(4)='0' then

if (inste(1) xor srcu) ='0' then

--Foreground 00 00m 0mm --

temp2:= mrf2; temp1:= mrf1; temp0:= mrf0;

else

-- Background 00 00m 100 --

temp2:= mrb2; temp1:= mrb1; temp0:= mrb0; end if; if inste(3)='0' then

-- Integer 00 000 mmm --

if inste(0)='0' then

-- Unsigned 00 000 mm0

if temp2(15 downto 0) /= X"0000" or temp1 /=X"00000000" then

temp2:= X"00000000"; temp1:= X"00000000"; temp0:= X"FFFFFFFF";

end if;

else

-- Signed 00 000 mm1 --

if temp2(15)='0'then

-- Positive --

if temp2(15 downto 0) /= X"0000" or temp1 /= X"00000000" or temp0(31)='1' then

temp2:= X"00000000"; temp1:= X"00000000"; temp0:= X"7FFFFFFF";

end if;

else

-- Negative --

if temp2(15 downto 0) /= X"FFFF" or temp1 /= X"FFFFFFFF" or temp0(31)='0' then

temp2:= X"FFFFFFFF"; temp1:= X"FFFFFFFF"; temp0:= X"80000000";

end if;

-- signe ou non else -- Fractional 00 001 mmm --

if inste(0)='0' then

-- Unsigned 00 001 mm0 --

if temp2(15 downto 0) /= X"0000" then

temp2:= X"00000000"; temp1:= X"FFFFFFFF"; temp0:= X"FFFFFFFF";

end if;

else

-- Signed 00 001 mm1 --

if temp2(15)='0' then

-- Positive --

if temp2(15 downto 0) /= X"0000" or temp1(31) = '1' then

temp2:= X"00000000"; temp1:= X"7FFFFFFF"; temp0:= X"FFFFFFFF";

end if;

else

-- Negative --

if temp2 /= X"0000FFFF" or temp1(31)= '0' then

temp2:= X"FFFFFFFF"; temp1:= X"80000000"; temp0:= X"00000000";

end if;

-- fractionnaire

--- Underflow Flag ---

if inste(3)='0' then

-- Integer --

MU := '0';

else

-- Fractional --

if inste(0)='1' and temp2(15)='1' then

-- Negative --

if temp2(15 downto 0)=X"FFFF" and temp1=X"FFFFFFFF" and temp0 /= X"00000000" then

MU :='1';

else MU :='0';

end if;

else

-- Positive --

if temp2(15 downto 0)=X"00000000" and temp1=X"00000000" and temp0 /= X"00000000" then

MU :='1';

else MU :='0';

end if;

-- underflow

if inste(2)='0' then

-- Resultat vers Reg File 00 00m 0xx

if inste(3)='0' then

-- Integer Data 00 000 0xx

MFR2F(7 downto 0) <= X"00"; MFR2F(39 downto 8)<= temp0;

else

-- Fractional Data 00 001 0xx

MFR2F(7 downto 0) <= X"00"; MFR2F(39 downto 8)<= temp1;

end if;

else

-- Resultat vers registres MR 00 00x 1mx

if (inste(1) xor srcu) ='0' then

-- Foreground 00 0X" 10x

mrf2 := temp2; mrf1 := temp1; mrf0 := temp0;

else

-- Background 00 0X" 11x

mrb2 := temp2; mrb1 := temp1; mrb0 := temp0;

end if;

if inste(0)='0' then

-- Unsigned --

MN :='0';

else

-- Signed --

MN := temp2(15); MI :='0'; MV :='0'; MF :='0';

end if;

-- end saturate ---------------------

-- Round MR ------------------ 00 011 mmx ----

if inste(4)='1' and inste(3)='1' then

if (inste(1) xor srcu) ='0' then

-- Foreground 00 011 00x

if mrf0>X"80000000" or (mrf1(0)='1' and mrf0=X"80000000") then

if mrf1=X"FFFFFFFF" then

temp0 := X"00000000"; temp1 := X"00000000"; temp2 := mrf2 + '1';

else temp0 := X"00000000"; temp1 := mrf1 + '1'; temp2 := mrf2;

end if;

else temp0 := X"00000000"; temp1 := mrf1; temp2 := mrf2;

end if;

else

-- Background 00 011 01x

if mrb0>X"80000000" or (mrb1(0)='1' and mrb0=X"80000000") then

if mrb1=X"FFFFFFFF" then

temp0 := X"00000000"; temp1 := X"00000000"; temp2 := mrb2 + '1';

else temp0 := X"00000000"; temp1 := mrb1 + '1'; temp2 := mrb2;

end if;

else temp0 := X"00000000"; temp1 := mrb1; temp2 := mrb2;

end if;

-- Foreground/Background

if inste(2)='0' then

-- Result to Register File --

MFR2F(7 downto 0) <= X"00"; MFR2F(39 downto 8) <= temp1;

else

-- Result to MR --

if (inste(1) xor srcu) ='0' then

-- Foreground --

mrf0 := temp0; mrf1 := temp1; mrf2 := temp2;

else

-- Background --

mrb0 := temp0; mrb1 := temp1; mrb2 := temp2;

end if;

--- Overflow flag ---

if inste(0)='1'and temp1(31)='1' then

-- Negative --

if temp2(15 downto 0)=X"FFFF" then

MV := '0';

else MV := '1';

end if;

else

-- Positive --

if temp2(15 downto 0)=X"0000"then

MV := '0'; else MV := '1';

end if;

MN := temp2(15); MU := '0'; MI := '0'; MF := '0';

end if;

-- end Round

end if; -- calcul sur registres MR

-- MULTIPLICATION FLOTTANT

if Inste(7)='0' and inste(6)='0' and inste(5)='1' and inste(4)='1' then

Mulf(XF, YF, PS_RND321F , PS_TRUNC1F, RF, MN, MI, MU, MV, MF); MFR2F <= RF;

end if;

-- MULTIPLICATION FIX

if Inste(7)='1' or inste(6)='1' then if inste(7)='1' then

----------- Accumulation

if (inste(1) xor srcu)='0' then

---- Foreground

temp0 :=mrf0; temp1 :=mrf1; temp2 :=mrf2;

else

---- Background

temp0 :=mrb0; temp1 :=mrb1; temp2 :=mrb2;

end if;

else temp0 :=X"00000000"; temp1 :=X"00000000"; temp2 :=X"00000000";

end if;

Mul(X,Y, Inste, temp0, temp1, temp2, MN, MI, MU, MV, MF);

if inste(2)='0' then

-- Resultat vers Reg File

if inste(3)='0' then

-- Integer Data

MFR2F(7 downto 0) <= X"00"; MFR2F(39 downto 8)<= temp0;

else -- Fractional Data

MFR2F(7 downto 0) <= X"00"; MFR2F(39 downto 8)<= temp1;

end if;

else

-- Resultat vers registres MR

if (inste(1) xor srcu) ='0' then

-- Foreground 00 0X" 10x

mrf2 := temp2; mrf1 := temp1; mrf0 := temp0;

else

-- Background 00 0X" 11x

mrb2 := temp2; mrb1 := temp1; mrb0 := temp0;

end if;

-- Multiplication Fix

end if;

---instructions de calcul

Stat2F<=(MN, MI, MU, MV, MF);

end if; -- Ck

end process;

end Multiplier_a;

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