i2c_arbitration.vhd

-- Wrapper for ipbus_i2c_master and ipbus_watchdog
--
-- Richard Staley, Nov 2017
 
library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
library ipbus_lib;
use ipbus_lib.ipbus.all;
 
entity ipbus_i2c_master_arb is
    generic(addr_width: natural := 0);
    port(
        clk: in std_logic;
        rst: in std_logic;
        ipb_in: in ipb_wbus;
        ipb_out: out ipb_rbus;
        scl: out std_logic;
        sda_o: out std_logic;
        sda_i: in std_logic := '0'
    );
    
end ipbus_i2c_master_arb;
 
architecture struct of ipbus_i2c_master_arb is
 
signal ipbw: ipb_wbus_array(1 downto 0);
signal ipbr: ipb_rbus_array(1 downto 0);
 
begin
 
block_decode: entity ipbus_lib.ipbus_fabric_branch
    generic map(
    NSLV => 2,
    DECODE_BASE => 3
    )
    port map(
        ipb_in => ipb_in,
        ipb_out => ipb_out,
        ipb_to_slaves => ipbw,
        ipb_from_slaves => ipbr
    );
 
-- the original i2c master
 
i2c_arp: entity ipbus_lib.ipbus_i2c_master
    port map(
        clk         => clk,
        rst        => rst,
        ipb_in    => ipbw(0),
        ipb_out => ipbr(0),
        scl         => scl,
        sda_o    => sda_o,
        sda_i     => sda_i
    );
 
-- arbitration register with key, lock and watchdog timer
 
arbitration: entity work.ipbus_watchdog
generic map(
    TIMER_WIDTH => 20
   )
    port map(
        ipbus_clk => clk,
        reset => rst,
        ipbus_in => ipbw(1),
        ipbus_out => ipbr(1)
     );
 
 
end struct;