//======================================================================
//
// novena_baseline_top.v
// ---------------------
// Top module for the Cryptech Novena FPGA framework. This design
// allow us to run the EIM interface at one clock and cores including
// core selector with the always present global clock.
//
//
// Author: Pavel Shatov
// Copyright (c) 2014, 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 novena_baseline_top
	(
		gclk_p_pin, gclk_n_pin,

		eim_bclk, eim_cs0_n, eim_da,
		eim_lba_n, eim_wr_n,
		eim_oe_n, eim_wait_n,

		reset_mcu_b_pin,
		apoptosis_pin,
		led_pin
	);

		//
		// Top-Levl Ports
		//
	input		wire				gclk_p_pin;			// general-purpose 50 MHz LVDS clock
	input		wire				gclk_n_pin;			//

	input		wire				eim_bclk;			// burst clock from cpu
	input		wire				eim_cs0_n;			// chip select (active low)
	inout		wire	[15: 0]	eim_da;				// bi-directional address/data bus
	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;			// wait signal (active low)

	input		wire				reset_mcu_b_pin;	// this must be configured as input w/pullup
															// not to kill the cpu after configuration
	output	wire				apoptosis_pin;		// not used, tied to 0
	output	wire				led_pin;				// visual activity indicator


		//
		// Clock Manager
		//

		/* Clock manager is used to buffer BCLK and also generate SYS_CLK from GCLK. */

	wire	sys_clk;
	wire	sys_rst;

	wire	eim_bclk_buf;

	novena_clkmgr clkmgr
	(
		.gclk_p			(gclk_p_pin),
		.gclk_n			(gclk_n_pin),

		.reset_mcu_b	(reset_mcu_b_pin),

		.sys_clk			(sys_clk),
		.sys_rst			(sys_rst),

		.bclk_in			(eim_bclk),
		.bclk_out		(eim_bclk_buf)
	);


		//
		// EIM Arbiter
		//

		/* EIM arbiter handles EIM access and transfers it into `sys_clk' clock domain. */

	wire	[13: 0]	sys_eim_addr;
	wire				sys_eim_wr;
	wire				sys_eim_rd;
	wire	[31: 0]	sys_eim_dout;
	wire	[31: 0]	sys_eim_din;

	eim_arbiter eim
	(
		.eim_bclk		(eim_bclk_buf),
		.eim_cs0_n		(eim_cs0_n),
		.eim_da			(eim_da),
		.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)
	);


		//
		// Core Selector (MUX)
		//

		/* This multiplexor is used to map demo adder registers somewhere into EIM address space. */

	core_selector mux
	(
		.sys_clk			(sys_clk),
		.sys_rst			(sys_rst),

		.sys_eim_addr	(sys_eim_addr),
		.sys_eim_wr		(sys_eim_wr),
		.sys_eim_rd		(sys_eim_rd),

		.sys_eim_dout	(sys_eim_dout),
		.sys_eim_din	(sys_eim_din)
	);


		//
		// LED Driver
		//
	eim_indicator led
	(
		.sys_clk			(sys_clk),
		.sys_rst			(sys_rst),
		.eim_active		(sys_eim_wr | sys_eim_rd),
		.led_out			(led_pin)
	);


		//
		// Unused
		//
	assign apoptosis_pin		= 1'b0;


endmodule

//======================================================================
// EOF novena_baseline_top.v
//======================================================================