//======================================================================
//
// alpha_top.v
// ------------
// Top module for the Cryptech Alpha FPGA framework. This design
// allow us to run the FMC interface at one clock and cores including
// core selector with the always present global clock.
//
//
// Author: Pavel Shatov
// Copyright (c) 2016, 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.
//
//======================================================================
`timescale 1ns / 1ps
module alpha_fmc_top
(
input wire gclk_pin, // 50 MHz
input wire ct_noise, // cryptech avalanche noise circuit
input wire fmc_clk, // clock
input wire [23: 0] fmc_a, // address
inout wire [31: 0] fmc_d, // data
input wire fmc_ne1, // chip select
input wire fmc_noe, // output enable
input wire fmc_nwe, // write enable
input wire fmc_nl, // latch enable
output wire fmc_nwait,// wait
output wire [3: 0] led_pins // {red, yellow, green, blue}
);
//----------------------------------------------------------------
// Clock Manager
//
// Clock manager is used to generate SYS_CLK from GCLK
// and implement the reset logic.
// ----------------------------------------------------------------
wire sys_clk;
wire sys_rst_n;
alpha_clkmgr #
(
.CLK_OUT_MUL (20.0), // 2..64
.CLK_OUT_DIV (20.0) // 1..128
)
clkmgr
(
.gclk (gclk_pin),
.sys_clk (sys_clk),
.sys_rst_n (sys_rst_n)
);
//----------------------------------------------------------------
// BUFG
//
// FMC clock must be routed through the global clocking backbone.
// ----------------------------------------------------------------
wire fmc_clk_bug;
BUFG BUFG_fmc_clk
(
.I (fmc_clk),
.O (fmc_clk_bufg)
);
//----------------------------------------------------------------
// FMC Arbiter
//
// FMC arbiter handles FMC access and transfers it into
// `sys_clk' clock domain.
//----------------------------------------------------------------
`define test
wire [23: 0] sys_fmc_addr; // address
wire sys_fmc_wren; // write enable
wire sys_fmc_rden; // read enable
wire [31: 0] sys_fmc_dout; // data output (from STM32 to FPGA)
`ifdef test
reg [31: 0] sys_fmc_din; // data input (from FPGA to STM32)
`else
wire [31: 0] sys_fmc_din; // data input (from FPGA to STM32)
`endif
fmc_arbiter #
(
.NUM_ADDR_BITS(24) // change to 26 when Alpha is alive!
)
fmc
(
.fmc_clk(fmc_clk_bufg),
.fmc_a(fmc_a),
.fmc_d(fmc_d),
.fmc_ne1(fmc_ne1),
.fmc_nl(fmc_nl),
.fmc_nwe(fmc_nwe),
.fmc_noe(fmc_noe),
.fmc_nwait(fmc_nwait),
.sys_clk(sys_clk),
.sys_addr(sys_fmc_addr),
.sys_wr_en(sys_fmc_wren),
.sys_rd_en(sys_fmc_rden),
.sys_data_out(sys_fmc_dout),
.sys_data_in(sys_fmc_din)
);
//----------------------------------------------------------------
// LED Driver
//
// A simple utility LED driver that turns on the Alpha
// board LED when the FMC interface is active.
//----------------------------------------------------------------
fmc_indicator led
(
.sys_clk(sys_clk),
.sys_rst_n(sys_rst_n),
.fmc_active(sys_fmc_wren | sys_fmc_rden),
.led_out(led_pins[0])
);
`ifdef test
//----------------------------------------------------------------
// Dummy Register
//
// General-purpose register to test FMC interface using STM32
// demo program instead of core selector logic.
//
// This register is a bit tricky, but it allows testing of both
// data and address buses. Reading from FPGA will always return
// value, which is currently stored in the test register,
// regardless of read transaction address. Writing to FPGA has
// two variants: a) writing to address 0 will store output data
// data value in the test register, b) writing to any non-zero
// address will store _address_ of write transaction in the test
// register.
//
// To test data bus, write some different patterns to address 0,
// then readback from any address and compare.
//
// To test address bus, write anything to some different non-zero
// addresses, then readback from any address and compare returned
// value with previously written address.
//
//----------------------------------------------------------------
reg [31: 0] test_reg;
//
// Noise Capture Register
//
reg [31: 0] noise_reg;
always @(posedge sys_clk)
//
noise_reg <= {noise_reg[30:0], ct_noise};
always @(posedge sys_clk)
//
if (sys_fmc_wren) begin
//
// when writing to address 0, store input data value
//
// when writing to non-zero address, store _address_
// (padded with zeroes) instead of data
//
test_reg <= (sys_fmc_addr == {24{1'b0}}) ? sys_fmc_dout : {{8{1'b0}}, sys_fmc_addr};
//
end else if (sys_fmc_rden) begin
//
// always return current value, ignore address
//
sys_fmc_din <= (sys_fmc_addr == {24{1'b1}}) ? noise_reg : test_reg;
// when reading from address 0, return the current value
// when reading from other addresses, return the address
//sys_fmc_din <= (sys_fmc_addr == {22{1'b0}}) ? test_reg : {{10{1'b0}}, sys_fmc_addr};
//
end
`else // !`ifdef test
//----------------------------------------------------------------
// Core Selector
//
// This multiplexer is used to map different types of cores, such as
// hashes, RNGs and ciphers to different regions (segments) of memory.
//----------------------------------------------------------------
core_selector cores
(
.sys_clk(sys_clk),
.sys_rst_n(sys_rst_n),
.sys_eim_addr(sys_fmc_addr[16:0]), // XXX parameterize
.sys_eim_wr(sys_fmc_wren),
.sys_eim_rd(sys_fmc_rden),
.sys_write_data(sys_fmc_dout),
.sys_read_data(sys_fmc_din),
.noise(ct_noise)
);
`endif
//
// Dummy assignment to bypass unconnected outpins pins check in BitGen
//
assign led_pins[3:1] = 3'b000;
endmodule
