11.2.1.1.5 Rising Edge Flip-Flop with Synchronous Reset

The following examples infer a D flip-flop with a synchronous reset.

Figure 11-6. D Flip-Flop with Synchronous Reset

VHDL

library IEEE;
use IEEE.std_logic_1164.all;
entity dff_sync_rst is
port (data, clk, reset : in std_logic;
q : out std_logic);
end dff_sync_rst;
architecture behav of dff_sync_rst is
begin
process (clk) begin
if (clk'event and clk = '1') then
if (reset = '0') then
q <= '0';
else q <= data;
end if;
end if;
end process;
end behav;

Verilog

module dff_sync_rst (data, clk, reset, q);
input data, clk, reset;
output q;
reg q;
always @ (posedge clk)
if (~reset)
q = 1'b0;
else q = data;
endmodule