//======================================================================
//
// coretest_hashes.v
// -----------------
// Top level wrapper that creates the Cryptech coretest system.
// The wrapper contains instances of external interface, coretest
// and the core to be tested. And if more than one core is
// present the wrapper also includes address and data muxes.
//
//
// Author: Pavel Shatov
// 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_memory
(
input wire sys_clk,
input wire sys_rst,
input wire [16: 0] sys_eim_addr,
input wire sys_eim_wr,
input wire sys_eim_rd,
output wire [31: 0] sys_read_data,
input wire [31: 0] sys_write_data
);
/* Three upper bits of address [16:14] are used to select memory segment.
* There can be eight segments. So far segment 0 is used for hashes,
* segment 1 is reserved for random number generators, segment 2 is reserved
* for chiphers. Other segments are not used so far.
*/
/* Every segment has its own memory map, take at look at corresponding selectors
* for more information.
*/
//----------------------------------------------------------------
// Segment Decoder
//----------------------------------------------------------------
localparam SEGMENT_ADDR_HASHES = 3'd0;
localparam SEGMENT_ADDR_RNGS = 3'd1;
localparam SEGMENT_ADDR_CIPHERS = 3'd2;
wire [ 2: 0] addr_segment = sys_eim_addr[16:14]; // 3 upper bits are decoded here
wire [13: 0] addr_segment_int = sys_eim_addr[13: 0]; // 14 lower bits are decoded individually
// in corresponding segment selectors
wire [31: 0] segment_hashes_read_data; // data read from HASHES segment
wire [31: 0] segment_rngs_read_data; // data read from RNGS segment
wire [31: 0] segment_ciphers_read_data; // data read from CIPHERS segment
wire segment_enable_hashes = (addr_segment == SEGMENT_ADDR_HASHES) ? 1'b1 : 1'b0; // HASHES segment is being addressed
wire segment_enable_rngs = (addr_segment == SEGMENT_ADDR_RNGS) ? 1'b1 : 1'b0; // RNGS segment is being addressed
wire segment_enable_ciphers = (addr_segment == SEGMENT_ADDR_CIPHERS) ? 1'b1 : 1'b0; // CIPHERS segment is being addressed
//----------------------------------------------------------------
// Output (Read Data) Bus
//----------------------------------------------------------------
reg [31: 0] sys_read_data_reg;
assign sys_read_data = sys_read_data_reg;
always @*
//
case (addr_segment)
SEGMENT_ADDR_HASHES: sys_read_data_reg = segment_hashes_read_data;
SEGMENT_ADDR_RNGS: sys_read_data_reg = segment_rngs_read_data;
SEGMENT_ADDR_CIPHERS: sys_read_data_reg = segment_ciphers_read_data;
default: sys_read_data_reg = {32{1'b0}};
endcase
//----------------------------------------------------------------
// HASH Core Selector
//
// This selector is used to map core registers into
// EIM address space and select which core to send EIM read and
// write operations to.
//----------------------------------------------------------------
core_selector segment_cores
(
.sys_clk(sys_clk),
.sys_rst(sys_rst),
.sys_ena(segment_enable_hashes), // only enable active selector
.sys_eim_addr(addr_segment_int), // we only connect 14 lower bits of address here,
// because we have already decoded 3 upper bits earlier,
// every segment can have its own address decoder.
.sys_eim_wr(sys_eim_wr),
.sys_eim_rd(sys_eim_rd),
.sys_write_data(sys_write_data),
.sys_read_data(segment_hashes_read_data) // output from HASHES segment
);
//----------------------------------------------------------------
// RNG Selector
//
// This selector is used to map random number generator registers into
// EIM address space and select which RNG to send EIM read and
// write operations to. So far there are no RNG cores.
//----------------------------------------------------------------
rng_selector segment_rngs
(
.sys_clk(sys_clk),
.sys_rst(sys_rst),
.sys_ena(segment_enable_rngs), // only enable active selector
.sys_eim_addr(addr_segment_int), // we only connect 14 lower bits of address here,
// because we have already decoded 3 upper bits earlier,
// every segment can have its own address decoder.
.sys_eim_wr(sys_eim_wr),
.sys_eim_rd(sys_eim_rd),
.sys_write_data(sys_write_data),
.sys_read_data(segment_rngs_read_data) // output from RNGS segment
);
//----------------------------------------------------------------
// CIPHER Selector
//
// This selector is used to map cipher registers into
// EIM address space and select which CIPHER to send EIM read and
// write operations to. So far there are no CIPHER cores.
//----------------------------------------------------------------
cipher_selector segment_ciphers
(
.sys_clk(sys_clk),
.sys_rst(sys_rst),
.sys_ena(segment_enable_ciphers), // only enable active selector
.sys_eim_addr(addr_segment_int), // we only connect 14 lower bits of address here,
// because we have already decoded 3 upper bits earlier,
// every segment can have its own address decoder.
.sys_eim_wr(sys_eim_wr),
.sys_eim_rd(sys_eim_rd),
.sys_write_data(sys_write_data),
.sys_read_data(segment_ciphers_read_data) // output from CIPHERS segment
);
endmodule
//======================================================================
// EOF eim_memory.v
//======================================================================
