bladeRF-wiphy/fpga/vhdl/wlan_dsss_rx_controller.vhd
2020-12-30 23:19:51 -08:00

82 lines
2.2 KiB
VHDL

-- This file is part of bladeRF-wiphy.
--
-- Copyright (C) 2020 Nuand, LLC.
--
-- This program is free software; you can redistribute it and/or modify
-- it under the terms of the GNU General Public License as published by
-- the Free Software Foundation; either version 2 of the License, or
-- (at your option) any later version.
--
-- This program 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. See the
-- GNU General Public License for more details.
--
-- You should have received a copy of the GNU General Public License along
-- with this program; if not, write to the Free Software Foundation, Inc.,
-- 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
library ieee ;
use ieee.std_logic_1164.all ;
use ieee.numeric_std.all ;
library wlan ;
use wlan.wlan_p.all ;
use wlan.wlan_rx_p.all ;
entity wlan_dsss_rx_controller is
port (
clock : in std_logic ;
reset : in std_logic ;
in_sample : in wlan_sample_t ;
modulation : out wlan_modulation_t;
out_bin_idx : out natural
) ;
end entity;
architecture arch of wlan_dsss_rx_controller is
type fsm_t is (IDLE) ;
type state_t is record
fsm : fsm_t ;
bin_idx : natural range 0 to 20 ;
end record ;
function NULL_STATE return state_t is
variable rv : state_t ;
begin
rv.fsm := IDLE ;
rv.bin_idx := 0 ;
return rv ;
end function ;
signal current, future : state_t := NULL_STATE ;
begin
out_bin_idx <= current.bin_idx ;
modulation <= WLAN_DBPSK ;
sync : process( clock )
begin
if( reset = '1' ) then
current <= NULL_STATE ;
elsif( rising_edge( clock ) ) then
current <= future ;
end if ;
end process ;
comb: process(all)
begin
future <= current ;
if( in_sample.valid = '1' ) then
if( current.bin_idx = 19 ) then
future.bin_idx <= 0 ;
else
future.bin_idx <= current.bin_idx + 1 ;
end if ;
end if ;
end process ;
end architecture ;