32-Bit Dynamic Shift Registers Coding Example (VHDL) - 32-Bit Dynamic Shift Registers Coding Example (VHDL) - 2022.2 English - UG901

Vivado Design Suite User Guide: Synthesis (UG901)

Document ID
UG901
Release Date
2022-11-16
Version
2022.2 English

Filename: dynamic_shift_registers_1.vhd

-- 32-bit dynamic shift register.

-- File:dynamic_shift_registers_1.vhd

-- 32-bit dynamic shift register.

library IEEE;

use IEEE.std_logic_1164.all;

use IEEE.std_logic_unsigned.all;

entity dynamic_shift_register_1 is

generic(

DEPTH     : integer := 32;

SEL_WIDTH : integer := 5

);

port(

CLK : in  std_logic;

SI  : in  std_logic;

CE  : in  std_logic;

A   : in  std_logic_vector(SEL_WIDTH - 1 downto 0);

DO  : out std_logic

);

end dynamic_shift_register_1;

architecture rtl of dynamic_shift_register_1 is

type SRL_ARRAY is array (DEPTH - 1 downto 0) of std_logic;

signal SRL_SIG : SRL_ARRAY;

begin

process(CLK)

begin

if rising_edge(CLK) then

if CE = '1' then

SRL_SIG <= SRL_SIG(DEPTH - 2 downto 0) & SI;

end if;

end if;

end process;

DO <= SRL_SIG(conv_integer(A));

end rtl;