How to calculate a power of y in VHDL ?

[Cutey]

Hi people
how to calculate X^y in VHDL, actually i have a program in vhdl to multiply two number using shift adder and I want to modify it to power of y.
here is my code multiply m by n, and I need to insert loop operation to work as multiply m by m for n time.....


rchitecture Behavioral of MUL is
signal count:integer:= 0;
signal n1,m1,nn:std_logic_vector(31 downto 0);
signal result1:std_logic_vector(63 downto 0);
begin
process(clk)

begin

if (rising_edge(clk))then
if( start = '1' )then
result<="0000000000000000000000000000000000000000000000000000000000000000";
result1<="0000000000000000000000000000000000000000000000000000000000000000";
count <=0;


else



if (count /= 32 )then
if (m1(0)='1')then
result1<=result1+n1;
end if ;
n1 <=n1(30 downto 0) & '0';
m1 <='0'& m1 (31 downto 1);
count <=count+1;
end if ;
end if;
end if ;
-- end loop;

result<=result1;

 

[TrickyDicky]

Re: Power of y in VHDL

This is not going to be trivial. Loops do not exist on hardware without some control logic. A loop in VHDL just unrolls to some parrallel hardware. This will give you a fixed amount of time always.
The best thing to do is find an algorithm to implement x^y and think about it in terms of hardware

 

[Cutey]

Re: Power of y in VHDL

even if don't use loop operation, I think it is possible to modify it by using if statement, am I correct?

 

[TrickyDicky]

Re: Power of y in VHDL

a x^y calculation will be a multi-stage pipeline.