Added systolic modular multiplier w/ testbench.

 * works in simulator
 * may have to change how internal operand buffer is pre-loaded
   (shift register instead of wide mux?)
 * code needs some cleanup

1 files changed, 545 insertions, 0 deletions

diff --git a/src/tb/tb_systolic_multiplier.v b/src/tb/tb_systolic_multiplier.v
new file mode 100644
index 0000000..3cbb8d1
--- /dev/null
+++ b/src/tb/tb_systolic_multiplier.v
@@ -0,0 +1,545 @@
+//======================================================================

+//

+// tb_systolic_multiplier.v

+// -----------------------------------------------------------------------------

+// Testbench for systolic Montgomery multiplier.

+//

+// Authors: Pavel Shatov

+//

+// Copyright (c) 2017, 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 tb_systolic_multiplier;

+

+	

+		//

+		// Test Vectors

+		//

+	`include "../modexp_fpga_model_vectors.v";

+	

+	

+		//

+		// Parameters

+		//

+	localparam NUM_WORDS_384 = 384 / 32;

+	localparam NUM_WORDS_512 = 512 / 32;

+	

+	

+		//

+		// Model Settings

+		//

+	localparam NUM_ROUNDS = 10;

+	

+	

+		//

+		// Clock (100 MHz)

+		//

+	reg clk = 1'b0;

+	always #5 clk = ~clk;

+	

+	

+		//

+		// Inputs

+		//

+	reg				rst_n;

+	reg				ena;

+	

+	reg	[ 3: 0]	n_num_words;

+

+

+		//

+		// Outputs

+		//

+	wire	rdy;

+

+

+		//

+		// Integers

+		//

+	integer w;

+	

+	

+		//

+		// BRAM Interfaces

+		//

+	wire	[ 3: 0]	core_a_addr;

+	wire	[ 3: 0]	core_b_addr;

+	wire	[ 3: 0]	core_n_addr;

+	wire	[ 3: 0]	core_n_coeff_addr;

+	wire	[ 3: 0]	core_r_addr;

+	

+	wire	[31: 0]	core_a_data;

+	wire	[31: 0]	core_b_data;

+	wire	[31: 0]	core_n_data;

+	wire	[31: 0]	core_n_coeff_data;

+	wire	[31: 0]	core_r_data;

+

+	wire				core_r_wren;

+

+	reg	[ 3: 0]	tb_abn_addr;
+	reg	[ 3: 0]	tb_r_addr;
+

+	reg	[31:0]	tb_a_data;
+	reg	[31:0]	tb_b_data;
+	reg	[31:0]	tb_n_data;
+	reg	[31:0]	tb_n_coeff_data;
+	wire	[31:0]	tb_r_data;
+	
+	reg				tb_abn_wren;
+	
+

+		//

+		// BRAMs

+		//

+	bram_1rw_1ro_readfirst #(.MEM_WIDTH(32), .MEM_ADDR_BITS(4))
+	bram_a (.clk(clk),

+		.a_addr(tb_abn_addr), .a_wr(tb_abn_wren), .a_in(tb_a_data), .a_out(),
+		.b_addr(core_a_addr), .b_out(core_a_data));
+

+	bram_1rw_1ro_readfirst #(.MEM_WIDTH(32), .MEM_ADDR_BITS(4))
+	bram_b (.clk(clk),

+		.a_addr(tb_abn_addr), .a_wr(tb_abn_wren), .a_in(tb_b_data), .a_out(),
+		.b_addr(core_b_addr), .b_out(core_b_data));
+

+	bram_1rw_1ro_readfirst #(.MEM_WIDTH(32), .MEM_ADDR_BITS(4))
+	bram_n (.clk(clk),

+		.a_addr(tb_abn_addr), .a_wr(tb_abn_wren), .a_in(tb_n_data), .a_out(),
+		.b_addr(core_n_addr), .b_out(core_n_data));
+

+	bram_1rw_1ro_readfirst #(.MEM_WIDTH(32), .MEM_ADDR_BITS(4))
+	bram_n_coeff (.clk(clk),

+		.a_addr(tb_abn_addr), .a_wr(tb_abn_wren), .a_in(tb_n_coeff_data), .a_out(),
+		.b_addr(core_n_coeff_addr), .b_out(core_n_coeff_data));
+

+	bram_1rw_1ro_readfirst #(.MEM_WIDTH(32), .MEM_ADDR_BITS(4))
+	bram_r (.clk(clk),

+		.a_addr(core_r_addr), .a_wr(core_r_wren), .a_in(core_r_data), .a_out(),
+		.b_addr(tb_r_addr), .b_out(tb_r_data));

+		
+

+		//

+		// UUT

+		//

+	modexpa7_systolic_multiplier #

+	(

+		.OPERAND_ADDR_WIDTH		(4),	// 32 * (2**4) = 512-bit operands

+		.SYSTOLIC_ARRAY_POWER	(2)	// 2 ** 2 = 4-tap array

+	)

+	uut

+	(

+		.clk						(clk), 

+		.rst_n					(rst_n), 

+		

+		.ena						(ena), 

+		.rdy						(rdy), 

+		

+		.a_bram_addr			(core_a_addr), 

+		.b_bram_addr			(core_b_addr), 

+		.n_bram_addr			(core_n_addr), 

+		.n_coeff_bram_addr	(core_n_coeff_addr), 

+		.r_bram_addr			(core_r_addr), 

+

+		.a_bram_out				(core_a_data), 

+		.b_bram_out				(core_b_data), 

+		.n_bram_out				(core_n_data), 

+		.n_coeff_bram_out		(core_n_coeff_data), 

+		

+		.r_bram_in				(core_r_data), 

+		.r_bram_wr				(core_r_wren), 

+		

+		.n_num_words			(n_num_words)

+	);

+

+

+		//

+		// Script

+		//

+	initial begin

+

+		rst_n = 1'b0;

+		ena = 1'b0;

+		

+		#200;		

+		rst_n = 1'b1;

+		#100;

+		

+		test_systolic_multiplier_384(M_384, N_384, N_COEFF_384, FACTOR_384, COEFF_384);

+		test_systolic_multiplier_512(M_512, N_512, N_COEFF_512, FACTOR_512, COEFF_512);

+		

+	end

+      

+		

+		//

+		// Test Tasks

+		//

+	task test_systolic_multiplier_384;
+	
+		input	[383:0] m;
+		input	[383:0] n;
+		input	[383:0] n_coeff;

+		input	[383:0] factor;

+		input [383:0] coeff;
+		

+		reg	[767:0] m_factor_full;

+		reg	[383:0] m_factor_modulo;

+		
+		reg	[383:0] a;
+		reg	[383:0] b;

+		reg	[383:0] r;

+	

+		reg	[767:0] ab_full;

+		reg	[383:0] ab_modulo;

+				

+		integer			round;

+		integer			num_passed;

+		integer			num_failed;

+	
+		begin
+			

+			m_factor_full = m * factor;					// m * factor

+			m_factor_modulo = m_factor_full % n;		// m * factor % n

+																	

+			m_factor_full = m_factor_modulo * coeff;	// m * factor * coeff

+			m_factor_modulo = m_factor_full % n;		// m * factor * coeff % n

+			

+			a = m_factor_modulo;								// start with a = m_factor...

+			b = m_factor_modulo;								// ... and b = m_factor

+

+			n_num_words = 4'd11;								// set number of words

+	

+			num_passed = 0;									// nothing tested so far

+			num_failed = 0;									//

+		

+			for (round=0; round<NUM_ROUNDS; round=round+1) begin

+			

+					// obtain reference value of product

+				ab_full  			= a * b;						// calculate product

+				ab_modulo			= ab_full % n;				// reduce

+	

+				ab_full				= ab_modulo * coeff;		// take extra coefficient into account

+				ab_modulo			= ab_full % n;				// reduce again

+

+				write_memories_384(a, b, n, n_coeff);		// fill memories

+			
+				ena = 1;												// start operation
+				#10;													//

+				ena = 0;												// clear flag
+			
+				while (!rdy) #10;									// wait for operation to complete
+

+				read_memory_384(r);								// get result from memory
+								

+				$display("test_systolic_multiplier_384(): round #%0d of %0d", round+1, NUM_ROUNDS);

+				$display("    calculated: %x", r);

+				$display("    expected:   %x", ab_modulo);

+								

+					// check calculated value

+				if (r === ab_modulo) begin
+					$display("        OK");

+					num_passed = num_passed + 1;
+				end else begin

+					$display("        ERROR");

+					num_failed = num_failed + 1;

+				end

+

+				b = ab_modulo;										// prepare for next round

+

+			end		

+		

+				// final step, display results

+			if (num_passed == NUM_ROUNDS)

+				$display("SUCCESS: All tests passed.");

+			else

+				$display("FAILURE: %0d test(s) not passed.", num_failed);

+		
+		end
+		
+	endtask
+

+

+		//

+		// Test Tasks

+		//

+	task test_systolic_multiplier_512;
+	
+		input	[ 511:0] m;
+		input	[ 511:0] n;
+		input	[ 511:0] n_coeff;

+		input	[ 511:0] factor;

+		input [ 511:0] coeff;
+		

+		reg	[1023:0] m_factor_full;

+		reg	[ 511:0] m_factor_modulo;

+		
+		reg	[ 511:0] a;
+		reg	[ 511:0] b;

+		reg	[ 511:0] r;

+	

+		reg	[1023:0] ab_full;

+		reg	[ 511:0] ab_modulo;

+				

+		integer			round;

+		integer			num_passed;

+		integer			num_failed;

+	
+		begin
+			

+			m_factor_full = m * factor;					// m * factor

+			m_factor_modulo = m_factor_full % n;		// m * factor % n

+																	

+			m_factor_full = m_factor_modulo * coeff;	// m * factor * coeff

+			m_factor_modulo = m_factor_full % n;		// m * factor * coeff % n

+			

+			a = m_factor_modulo;								// start with a = m_factor...

+			b = m_factor_modulo;								// ... and b = m_factor

+

+			n_num_words = 4'd15;								// set number of words

+	

+			num_passed = 0;									// nothing tested so far

+			num_failed = 0;									//

+		

+			for (round=0; round<NUM_ROUNDS; round=round+1) begin

+			

+					// obtain reference value of product

+				ab_full  			= a * b;						// calculate product

+				ab_modulo			= ab_full % n;				// reduce

+	

+				ab_full				= ab_modulo * coeff;		// take extra coefficient into account

+				ab_modulo			= ab_full % n;				// reduce again

+

+				write_memories_512(a, b, n, n_coeff);		// fill memories

+			
+				ena = 1;												// start operation
+				#10;													//

+				ena = 0;												// clear flag
+			
+				while (!rdy) #10;									// wait for operation to complete
+

+				read_memory_512(r);								// get result from memory
+								

+				$display("test_systolic_multiplier_512(): round #%0d of %0d", round+1, NUM_ROUNDS);

+				$display("    calculated: %x", r);

+				$display("    expected:   %x", ab_modulo);

+								

+					// check calculated value

+				if (r === ab_modulo) begin
+					$display("        OK");

+					num_passed = num_passed + 1;
+				end else begin

+					$display("        ERROR");

+					num_failed = num_failed + 1;

+				end

+

+				b = ab_modulo;										// prepare for next round

+

+			end		

+		

+				// final step, display results

+			if (num_passed == NUM_ROUNDS)

+				$display("SUCCESS: All tests passed.");

+			else

+				$display("FAILURE: %0d test(s) not passed.", num_failed);

+		
+		end
+		
+	endtask

+	

+	

+		//

+		// BRAM Writer

+		//

+	task write_memories_384;

+

+		input	[383:0] a;
+		input	[383:0] b;
+		input	[383:0] n;

+		input	[383:0] n_coeff;

+		

+		reg	[383:0] a_shreg;

+		reg	[383:0] b_shreg;

+		reg	[383:0] n_shreg;

+		reg	[383:0] n_coeff_shreg;

+		

+		begin
+			

+			tb_abn_wren	= 1;														// start filling memories
+			
+			a_shreg       = a;													// initialize shift registers
+			b_shreg       = b;													//
+			n_shreg       = n;													//

+			n_coeff_shreg = n_coeff;											//
+			
+			for (w=0; w<NUM_WORDS_384; w=w+1) begin						// write all words
+				
+				tb_abn_addr	= w[3:0];											// set addresses
+				
+				tb_a_data       = a_shreg[31:0];								// set data words
+				tb_b_data       = b_shreg[31:0];								//
+				tb_n_data       = n_shreg[31:0];								//

+				tb_n_coeff_data = n_coeff_shreg[31:0];						//
+				
+				a_shreg       = {{32{1'bX}}, a_shreg[383:32]};			// shift inputs
+				b_shreg       = {{32{1'bX}}, b_shreg[383:32]};			//
+				n_shreg       = {{32{1'bX}}, n_shreg[383:32]};			//

+				n_coeff_shreg = {{32{1'bX}}, n_coeff_shreg[383:32]};	//
+				
+				#10;																	// wait for 1 clock tick
+				
+			end
+			
+			tb_abn_addr	= {4{1'bX}};											// wipe addresses
+			
+			tb_a_data       = {32{1'bX}};										// wipe data words
+			tb_b_data       = {32{1'bX}};										//
+			tb_n_data       = {32{1'bX}};										//

+			tb_n_coeff_data = {32{1'bX}};										//
+			
+			tb_abn_wren = 0;														// stop filling memories

+		

+		end

+		

+	endtask
+		

+		

+		//

+		// BRAM Writer

+		//

+	task write_memories_512;

+

+		input	[511:0] a;
+		input	[511:0] b;
+		input	[511:0] n;

+		input	[511:0] n_coeff;

+		

+		reg	[511:0] a_shreg;

+		reg	[511:0] b_shreg;

+		reg	[511:0] n_shreg;

+		reg	[511:0] n_coeff_shreg;

+		

+		begin
+			

+			tb_abn_wren	= 1;														// start filling memories
+			
+			a_shreg       = a;													// initialize shift registers
+			b_shreg       = b;													//
+			n_shreg       = n;													//

+			n_coeff_shreg = n_coeff;											//
+			
+			for (w=0; w<NUM_WORDS_512; w=w+1) begin						// write all words
+				
+				tb_abn_addr	= w[3:0];											// set addresses
+				
+				tb_a_data       = a_shreg[31:0];								// set data words
+				tb_b_data       = b_shreg[31:0];								//
+				tb_n_data       = n_shreg[31:0];								//

+				tb_n_coeff_data = n_coeff_shreg[31:0];						//
+				
+				a_shreg       = {{32{1'bX}}, a_shreg[511:32]};			// shift inputs
+				b_shreg       = {{32{1'bX}}, b_shreg[511:32]};			//
+				n_shreg       = {{32{1'bX}}, n_shreg[511:32]};			//

+				n_coeff_shreg = {{32{1'bX}}, n_coeff_shreg[511:32]};	//
+				
+				#10;																	// wait for 1 clock tick
+				
+			end
+			
+			tb_abn_addr	= {4{1'bX}};											// wipe addresses
+			
+			tb_a_data       = {32{1'bX}};										// wipe data words
+			tb_b_data       = {32{1'bX}};										//
+			tb_n_data       = {32{1'bX}};										//

+			tb_n_coeff_data = {32{1'bX}};										//
+			
+			tb_abn_wren = 0;														// stop filling memories

+		

+		end

+		

+	endtask

+	
+

+		//

+		// BRAM Reader

+		//

+	task read_memory_384;

+

+		output	[383:0] r;

+		reg		[383:0] r_shreg;

+		

+		begin
+			

+			for (w=0; w<NUM_WORDS_384; w=w+1) begin		// read result
+				
+				tb_r_addr = w[3:0];								// set address
+				#10;													// wait for 1 clock tick
+				r_shreg = {tb_r_data, r_shreg[383:32]};	// store data word
+
+			end				
+		

+			tb_r_addr = {4{1'bX}};								// wipe address

+			r = r_shreg;											// return

+

+		end		

+		

+	endtask
+

+

+		//

+		// BRAM Reader

+		//

+	task read_memory_512;

+

+		output	[511:0] r;

+		reg		[511:0] r_shreg;

+		

+		begin
+			

+			for (w=0; w<NUM_WORDS_512; w=w+1) begin		// read result
+				
+				tb_r_addr = w[3:0];								// set address
+				#10;													// wait for 1 clock tick
+				r_shreg = {tb_r_data, r_shreg[511:32]};	// store data word
+
+			end				
+		

+			tb_r_addr = {4{1'bX}};								// wipe address

+			r = r_shreg;											// return

+

+		end		

+		

+	endtask
+

+

+endmodule

+

+//======================================================================

+// End of file

+//======================================================================