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//======================================================================
//
// Copyright (c) 2014-2015, NORDUnet A/S All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
// - Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
//
// - Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// - Neither the name of the NORDUnet nor the names of its contributors may
// be used to endorse or promote products derived from this software
// without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
// IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
// PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
// TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
//======================================================================
module eim
(
// EIM interface pins from CPU
input wire eim_bclk, // EIM burst clock. Started by the CPU.
input wire eim_cs0_n, // Chip select (active low).
inout wire [15 : 0] eim_da, // Bidirectional address and data port.
input wire [18: 16] eim_a, // MSB part of address port.
input wire eim_lba_n, // Latch address signal (active low).
input wire eim_wr_n, // write enable signal (active low).
input wire eim_oe_n, // output enable signal (active low).
output wire eim_wait_n, // Data wait signal (active low).
// system clock and reset
input wire sys_clk,
input wire sys_rst_n,
// EIM interface to cores
output wire [16: 0] sys_eim_addr,
output wire sys_eim_wr,
output wire sys_eim_rd,
output wire [31: 0] sys_eim_dout,
input wire [31: 0] sys_eim_din,
// Novena utility ports
output wire led_pin // LED on edge close to the FPGA.
);
//----------------------------------------------------------------
// EIM Arbiter
//
// EIM arbiter handles EIM access and transfers it into
// `sys_clk' clock domain.
//----------------------------------------------------------------
eim_arbiter eim
(
.eim_bclk(eim_bclk),
.eim_cs0_n(eim_cs0_n),
.eim_da(eim_da),
.eim_a(eim_a),
.eim_lba_n(eim_lba_n),
.eim_wr_n(eim_wr_n),
.eim_oe_n(eim_oe_n),
.eim_wait_n(eim_wait_n),
.sys_clk(sys_clk),
.sys_addr(sys_eim_addr),
.sys_wren(sys_eim_wr),
.sys_data_out(sys_eim_dout),
.sys_rden(sys_eim_rd),
.sys_data_in(sys_eim_din)
);
//----------------------------------------------------------------
// LED Driver
//
// A simple utility LED driver that turns on the Novena
// board LED when the EIM interface is active.
//----------------------------------------------------------------
eim_indicator led
(
.sys_clk(sys_clk),
.sys_rst_n(sys_rst_n),
.eim_active(sys_eim_wr | sys_eim_rd),
.led_out(led_pin)
);
endmodule // eim
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