pluto_hdl_adi/library/common/axi_streaming_dma_rx_fifo.vhd

118 lines
3.5 KiB
VHDL

-- ***************************************************************************
-- ***************************************************************************
-- Copyright 2014 - 2017 (c) Analog Devices, Inc. All rights reserved.
--
-- In this HDL repository, there are many different and unique modules, consisting
-- of various HDL (Verilog or VHDL) components. The individual modules are
-- developed independently, and may be accompanied by separate and unique license
-- terms.
--
-- The user should read each of these license terms, and understand the
-- freedoms and responsibilities that he or she has by using this source/core.
--
-- This core is distributed in the hope that it will be useful, but WITHOUT ANY
-- WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
-- A PARTICULAR PURPOSE.
--
-- Redistribution and use of source or resulting binaries, with or without modification
-- of this file, are permitted under one of the following two license terms:
--
-- 1. The GNU General Public License version 2 as published by the
-- Free Software Foundation, which can be found in the top level directory
-- of this repository (LICENSE_GPL2), and also online at:
-- <https://www.gnu.org/licenses/old-licenses/gpl-2.0.html>
--
-- OR
--
-- 2. An ADI specific BSD license, which can be found in the top level directory
-- of this repository (LICENSE_ADIBSD), and also on-line at:
-- https://github.com/analogdevicesinc/hdl/blob/master/LICENSE_ADIBSD
-- This will allow to generate bit files and not release the source code,
-- as long as it attaches to an ADI device.
--
-- ***************************************************************************
-- ***************************************************************************
library ieee;
use ieee.std_logic_1164.all;
library work;
use work.dma_fifo;
entity axi_streaming_dma_rx_fifo is
generic (
RAM_ADDR_WIDTH : integer := 3;
FIFO_DWIDTH : integer := 32
);
port (
clk : in std_logic;
resetn : in std_logic;
fifo_reset : in std_logic;
-- Enable DMA interface
enable : in Boolean;
period_len : in integer range 0 to 65535;
-- Read port
m_axis_aclk : in std_logic;
m_axis_tready : in std_logic;
m_axis_tdata : out std_logic_vector(FIFO_DWIDTH-1 downto 0);
m_axis_tlast : out std_logic;
m_axis_tvalid : out std_logic;
m_axis_tkeep : out std_logic_vector(3 downto 0);
-- Write port
in_stb : in std_logic;
in_ack : out std_logic;
in_data : in std_logic_vector(FIFO_DWIDTH-1 downto 0)
);
end;
architecture imp of axi_streaming_dma_rx_fifo is
signal out_stb : std_logic;
signal period_count : integer range 0 to 65535;
signal last : std_logic;
begin
m_axis_tvalid <= out_stb;
fifo: entity dma_fifo
generic map (
RAM_ADDR_WIDTH => RAM_ADDR_WIDTH,
FIFO_DWIDTH => FIFO_DWIDTH
)
port map (
clk => clk,
resetn => resetn,
fifo_reset => fifo_reset,
in_stb => in_stb,
in_ack => in_ack,
in_data => in_data,
out_stb => out_stb,
out_ack => m_axis_tready,
out_data => m_axis_tdata
);
m_axis_tkeep <= "1111";
m_axis_tlast <= '1' when period_count = 0 else '0';
period_counter: process(m_axis_aclk) is
begin
if rising_edge(m_axis_aclk) then
if resetn = '0' then
period_count <= period_len;
else
if out_stb = '1' and m_axis_tready = '1' then
if period_count = 0 then
period_count <= period_len;
else
period_count <= period_count - 1;
end if;
end if;
end if;
end if;
end process;
end;