FOR LOOP using a Variable: 4-bit Left Shifter

Enables shift-left

i is the index for the FOR LOOP

and does not need to be declared

Shifts left by 4

Fills the LSBs with zeros

No shifting

Variable is assigned to a Signal before the end of the Process to synthesize to a piece of hardware

IF shft_lft = '1' THEN

FOR i IN 7 DOWNTO 4 LOOP

shft_var(i) := shft_var(i-4);

END LOOP;

shft_var(3 downto 0) := “0000”;

ELSE

shft_var := shft_var;

END IF;

q_out <= shft_var;

END PROCESS;

END logic;