From 0da71205b28d07cc832732b28e8893c46fbf6cad Mon Sep 17 00:00:00 2001
From: "Pavel V. Shatov (Meister)" <meisterpaul1@yandex.ru>
Date: Tue, 4 Jul 2017 16:33:04 +0300
Subject: Fixed generic/vendor low-level primitives switch.

---
 src/rtl/modexpa7_factor.v                |   2 +-
 src/rtl/modexpa7_n_coeff.v               |   8 +-
 src/rtl/modexpa7_systolic_multiplier.v   |  10 +-
 src/rtl/pe/artix7/dsp48e1_wrapper_ext.v  | 159 +++++++++++++++++++++++
 src/rtl/pe/artix7/multiplier32_artix7.v  | 208 ++++++++++++++++++++++---------
 src/rtl/pe/artix7/systolic_pe_artix7.v   | 126 +++++++++++++++++++
 src/rtl/pe/generic/systolic_pe_generic.v |  85 +++++++++++++
 src/rtl/pe/modexpa7_adder32.v            |  76 +++++++++++
 src/rtl/pe/modexpa7_lowlevel_settings.v  |  15 +++
 src/rtl/pe/modexpa7_subtractor32.v       |  76 +++++++++++
 src/rtl/pe/modexpa7_systolic_pe.v        |  75 +++++++++++
 11 files changed, 770 insertions(+), 70 deletions(-)
 create mode 100644 src/rtl/pe/artix7/dsp48e1_wrapper_ext.v
 create mode 100644 src/rtl/pe/artix7/systolic_pe_artix7.v
 create mode 100644 src/rtl/pe/generic/systolic_pe_generic.v
 create mode 100644 src/rtl/pe/modexpa7_adder32.v
 create mode 100644 src/rtl/pe/modexpa7_lowlevel_settings.v
 create mode 100644 src/rtl/pe/modexpa7_subtractor32.v
 create mode 100644 src/rtl/pe/modexpa7_systolic_pe.v

(limited to 'src/rtl')

diff --git a/src/rtl/modexpa7_factor.v b/src/rtl/modexpa7_factor.v
index b3ad130..3f90e5d 100644
--- a/src/rtl/modexpa7_factor.v
+++ b/src/rtl/modexpa7_factor.v
@@ -276,7 +276,7 @@ module modexpa7_factor #
 			/* mask borrow into the very first word */
 		sub_b_in_mask <= (fsm_next_state == FSM_STATE_CALC_3) ? 1'b1 : 1'b0;
 		
-	modexpa7_pe_sub sub_inst
+	modexpa7_subtractor32 sub_inst
 	(
 		.clk		(clk),
 		.ce		(1'b1),
diff --git a/src/rtl/modexpa7_n_coeff.v b/src/rtl/modexpa7_n_coeff.v
index d416898..c2d7c9d 100644
--- a/src/rtl/modexpa7_n_coeff.v
+++ b/src/rtl/modexpa7_n_coeff.v
@@ -315,10 +315,10 @@ module modexpa7_n_coeff #
 		/* delay carry masking flag by one clock cycle (used later) */
 	always @(posedge clk) add1_c_in_mask_dly <= add1_c_in_mask;
 	
-	modexpa7_pe_add add1_inst
+	modexpa7_adder32 add1_inst
 	(
 		.clk		(clk),								//
-		.ce		(1'b1),
+		.ce		(1'b1),								//
 		.a			(~n_bram_out),						// ~N
 		.b			({{31{1'b0}}, add1_b_lsb}),	//  1
 		.c_in		(add1_c_in),						//
@@ -339,7 +339,7 @@ module modexpa7_n_coeff #
 	reg				add2_c_in;		// carry input
 	wire				add2_c_out;		// carry output
 			
-	modexpa7_pe_add add2_inst
+	modexpa7_adder32 add2_inst
 	(
 		.clk		(clk),
 		.ce		(1'b1),
@@ -367,7 +367,7 @@ module modexpa7_n_coeff #
 	wire	[31: 0]	pe_p;
 	wire	[31: 0]	pe_c_out;
 		
-	modexpa7_pe_mul pe_mul_inst
+	modexpa7_systolic_pe pe_mul_inst
 	(
 		.clk		(clk),
 		.a			(pe_a),
diff --git a/src/rtl/modexpa7_systolic_multiplier.v b/src/rtl/modexpa7_systolic_multiplier.v
index fa99c54..cb1c716 100644
--- a/src/rtl/modexpa7_systolic_multiplier.v
+++ b/src/rtl/modexpa7_systolic_multiplier.v
@@ -400,7 +400,7 @@ module modexpa7_systolic_multiplier #
 	generate for (syst=0; syst<SYSTOLIC_ARRAY_LENGTH; syst=syst+1)
 		begin : gen_mul
 	
-			modexpa7_pe_mul mul_ab_inst
+			modexpa7_systolic_pe mul_ab_inst
 			(
 				.clk		(clk),
 				.a			(mul_ab_a),
@@ -412,7 +412,7 @@ module modexpa7_systolic_multiplier #
 				.c_out	(mul_ab_c_out[syst])
 			);
 			
-			modexpa7_pe_mul mul_q_inst
+			modexpa7_systolic_pe mul_q_inst
 			(
 				.clk		(clk),
 				.a			(mul_q_a),
@@ -425,7 +425,7 @@ module modexpa7_systolic_multiplier #
 			);
 			
 
-			modexpa7_pe_mul mul_qn_inst
+			modexpa7_systolic_pe mul_qn_inst
 			(
 				.clk		(clk),
 				.a			(mul_qn_a),
@@ -616,7 +616,7 @@ module modexpa7_systolic_multiplier #
 			pe_sub_b_in <= (mult_cnt_s == mult_cnt_zero) ? 1'b0 : pe_sub_b_out;
 	
 	
-	modexpa7_pe_add pe_add_inst
+	modexpa7_adder32 pe_add_inst
 	(
 		.clk		(clk),
 		.ce		(pe_add_ce),
@@ -627,7 +627,7 @@ module modexpa7_systolic_multiplier #
 		.c_out	(pe_add_c_out)
 	);
 
-	modexpa7_pe_sub pe_sub_inst
+	modexpa7_subtractor32 pe_sub_inst
 	(
 		.clk		(clk),
 		.ce		(pe_sub_ce),
diff --git a/src/rtl/pe/artix7/dsp48e1_wrapper_ext.v b/src/rtl/pe/artix7/dsp48e1_wrapper_ext.v
new file mode 100644
index 0000000..83fb78c
--- /dev/null
+++ b/src/rtl/pe/artix7/dsp48e1_wrapper_ext.v
@@ -0,0 +1,159 @@
+//------------------------------------------------------------------------------
+//
+// dsp48e1_wrapper_ext.v
+// -----------------------------------------------------------------------------
+// Extended hardware (Artix-7 DSP48E1) tile wrapper.
+//
+// Authors: Pavel Shatov
+//
+// Copyright (c) 2016-2017, NORDUnet A/S
+//
+// 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 dsp48e1_wrapper_ext #
+	(
+		parameter	AREG		= 1'b0,
+		parameter	PREG		= 1'b0,
+		
+		parameter	A_INPUT	= "DIRECT"
+	)
+	(
+		input					clk,
+		input		[ 6: 0]	opmode,
+		input		[29: 0]	a,
+		input		[17: 0]	b,
+		output	[47: 0]	p,
+		input		[29: 0]	acin,
+		input		[47: 0]	pcin,
+		output	[29: 0]	acout,
+		output	[47: 0]	pcout
+	);
+	
+		//
+		// Tile instantiation
+		//
+	DSP48E1 #
+	(
+		.AREG						(AREG),
+		.BREG						(1'b1),
+		.CREG						(0),
+		.DREG						(0),
+		.MREG						(0),
+		.PREG						(PREG),
+		.ADREG					(0),
+		
+		.ACASCREG				(AREG),
+		.BCASCREG				(1'b1),
+		.ALUMODEREG				(0),
+		.INMODEREG				(0),
+		.OPMODEREG				(0),
+		.CARRYINREG				(0),
+		.CARRYINSELREG			(0),
+
+		.A_INPUT					(A_INPUT),
+		.B_INPUT					("DIRECT"),
+		
+		.USE_DPORT				("FALSE"),
+		.USE_MULT				("MULTIPLY"),
+		.USE_SIMD				("ONE48"),
+
+		.USE_PATTERN_DETECT	("NO_PATDET"),
+		.SEL_PATTERN			("PATTERN"),
+		.SEL_MASK				("MASK"),
+		.PATTERN					(48'h000000000000),
+		.MASK						(48'h3fffffffffff),
+		.AUTORESET_PATDET		("NO_RESET")
+	)
+	DSP48E1_inst
+	(
+		.CLK					(clk),
+
+		.RSTA					(1'b0),
+		.RSTB					(1'b0),
+		.RSTC					(1'b0),
+		.RSTD					(1'b0),
+		.RSTM					(1'b0),
+		.RSTP					(1'b0),
+
+		.RSTCTRL				(1'b0),
+		.RSTINMODE			(1'b0),
+		.RSTALUMODE			(1'b0),
+		.RSTALLCARRYIN		(1'b0),
+
+		.CEA1					(1'b0),
+		.CEA2					(AREG),
+		.CEB1					(1'b0),
+		.CEB2					(1'b1),
+		.CEC					(1'b0),
+		.CED					(1'b0),
+		.CEM					(1'b0),
+		.CEP					(PREG),
+		.CEAD					(1'b0),
+		.CEALUMODE			(1'b0),
+		.CEINMODE			(1'b0),
+
+		.CECTRL				(1'b0),
+		.CECARRYIN			(1'b0),
+
+		.A						(a),
+		.B						(b),
+		.C						({48{1'b0}}),
+		.D						({25{1'b1}}),
+		.P						(p),
+
+		.CARRYIN				(1'b0),
+		.CARRYOUT			(),
+		.CARRYINSEL			(3'b000),
+
+		.CARRYCASCIN		(1'b0),
+		.CARRYCASCOUT		(),
+
+		.PATTERNDETECT		(),
+		.PATTERNBDETECT	(),
+
+		.OPMODE				(opmode),
+		.ALUMODE				(4'b0000),
+		.INMODE				(5'b00000),
+
+		.MULTSIGNIN			(1'b0),
+		.MULTSIGNOUT		(),
+
+		.UNDERFLOW			(),
+		.OVERFLOW			(),
+
+		.ACIN					(acin),
+		.BCIN					(18'd0),
+		.PCIN					(pcin),
+
+		.ACOUT				(acout),
+		.BCOUT				(),
+		.PCOUT				(pcout)
+  );
+
+endmodule
diff --git a/src/rtl/pe/artix7/multiplier32_artix7.v b/src/rtl/pe/artix7/multiplier32_artix7.v
index 5cc6340..1fc6d30 100644
--- a/src/rtl/pe/artix7/multiplier32_artix7.v
+++ b/src/rtl/pe/artix7/multiplier32_artix7.v
@@ -1,83 +1,171 @@
-`timescale 1ns / 1ps
+//------------------------------------------------------------------------------
+//
+// multiplier32_artix7.v
+// -----------------------------------------------------------------------------
+// Hardware (Artix-7 DSP48E1) 32-bit multiplier.
+//
+// Authors: Pavel Shatov
+//
+// Copyright (c) 2016-2017, NORDUnet A/S
+//
+// 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 multiplier32_artix7
 	(
 		input					clk,
 		input		[31: 0]	a,
 		input		[31: 0]	b,
-		input		[31: 0]	t,
-		input		[31: 0]	c_in,
-		output	[31: 0]	p,
-		output	[31: 0]	c_out
+		output	[63: 0]	p
 	);
+
+		/* split a, b into smaller words */
+	wire	[16: 0]	a_lo = a[16: 0];
+	wire	[16: 0]	b_lo = b[16: 0];
+	wire	[14: 0]	a_hi = a[31:17];
+	wire	[14: 0]	b_hi = b[31:17];
+
+		/* smaller sub-products */
+	wire	[47: 0]	dsp1_p;
+	wire	[47: 0]	dsp2_p;
+	wire	[47: 0]	dsp4_p;
+
+		/* direct output mapping */
+	assign p[63:34] = dsp4_p[29: 0];
 	
-	reg	[31: 0]	t_dly;
-	reg	[31: 0]	c_in_dly;
-	
-	always @(posedge clk) t_dly <= t;
-	always @(posedge clk) c_in_dly <= c_in;
-	
-	wire	[31: 0]	t_c_in_s;
-	wire				t_c_in_c_out;
-	
-	reg				t_c_in_c_out_dly;
-	
-	always @(posedge clk) t_c_in_c_out_dly <= t_c_in_c_out;
+		/* delayed output mapping */
+	genvar fd;
+	generate for (fd=0; fd<17; fd=fd+1)
+		begin : gen_FD
+			FD # (.INIT( 1'b0)) FD_inst1 (.C(clk), .D(dsp1_p[fd]), .Q(p[fd +  0]));
+			FD # (.INIT( 1'b0)) FD_inst3 (.C(clk), .D(dsp2_p[fd]), .Q(p[fd + 17]));
+		end
+	endgenerate
+
+		/* product chains */
+	wire	[47: 0]	dsp1_p_chain;
+	wire	[47: 0]	dsp3_p_chain;
+	wire	[47: 0]	dsp2_p_chain;
 	
-	adder32_artix7 add_t_c_in
+		/* operand chains */
+	wire	[29: 0]	a_lo_chain;
+	wire	[29: 0]	a_hi_chain;  
+  
+		//
+		// a_lo * b_lo
+		//
+	dsp48e1_wrapper_ext #
+	(
+		.AREG			(1'b1),
+		.PREG			(1'b0),
+		.A_INPUT		("DIRECT")
+	)
+	dsp1
 	(
 		.clk		(clk),
-		.a			(t_dly),
-		.b			(c_in_dly),
-		.c_in		(1'b0),
-		.s			(t_c_in_s),
-		.c_out	(t_c_in_c_out)
+		.opmode	(7'b0110101),
+		.a			({13'd0, a_lo}),
+		.b			({1'b0, b_lo}),
+		.p			(dsp1_p),
+		.acin		(30'd0),
+		.pcin		(48'd0),
+		.acout	(a_lo_chain),
+		.pcout	(dsp1_p_chain)
 	);
-
-	wire	[63: 0]	a_b;
-	
-	wire	[31: 0]	a_b_lsb = a_b[31: 0];
-	wire	[31: 0]	a_b_msb = a_b[63:32];
-	
-	reg	[31: 0]	a_b_msb_dly;
-	
-	always @(posedge clk) a_b_msb_dly <= a_b_msb;
 	
-	ip_mul32 mul_a_b
+		//
+		// a_hi * b_lo
+		//
+	dsp48e1_wrapper_ext #
 	(
-		.clk	(clk),
-		.a		(a),
-		.b		(b),
-		.p		(a_b)
+		.AREG			(1'b1),
+		.PREG			(1'b0),
+		.A_INPUT		("DIRECT")
+	)
+	dsp2
+	(
+		.clk		(clk),
+		.opmode	(7'b0010101),
+		.a			({15'd0, a_hi}),
+		.b			({1'd0, b_lo}),
+		.p			(dsp2_p),
+		.acin		(30'd0),
+		.pcin		(dsp3_p_chain),
+		.acout	(a_hi_chain),
+		.pcout	(dsp2_p_chain)
 	);
 	
-	wire	[31: 0]	add_p_s;
-	wire				add_p_c_out;
-	
-	reg	[31: 0]	add_p_s_dly;
-	
-	always @(posedge clk) add_p_s_dly <= add_p_s;
-	
-	assign p = add_p_s_dly;
-	
-	adder32_artix7 add_p
+		//
+		// a_lo * b_hi
+		//
+	dsp48e1_wrapper_ext #
+	(
+		.AREG			(1'b0),
+		.PREG			(1'b0),
+		.A_INPUT		("CASCADE")
+	)
+	dsp3
 	(
 		.clk		(clk),
-		.a			(a_b_lsb),
-		.b			(t_c_in_s),
-		.c_in		(1'b0),
-		.s			(add_p_s),
-		.c_out	(add_p_c_out)
-	);
-
-	adder32_artix7 add_c_out
+		.opmode	(7'b1010101),
+		.a			(30'd0),
+		.b			({3'd0, b_hi}),
+		.p			(),
+		.acin		(a_lo_chain),
+		.pcin		(dsp1_p_chain),
+		.acout	(),
+		.pcout	(dsp3_p_chain)
+	);	
+	
+		//
+		// a_hi * b_hi
+		//
+	dsp48e1_wrapper_ext #
+	(
+		.AREG			(1'b0),
+		.PREG			(1'b1),
+		.A_INPUT		("CASCADE")
+	)
+	dsp4
 	(
 		.clk		(clk),
-		.a			(a_b_msb_dly),
-		.b			({{31{1'b0}}, t_c_in_c_out_dly}),
-		.c_in		(add_p_c_out),
-		.s			(c_out),
-		.c_out	()
+		.opmode	(7'b1010101),
+		.a			(30'd0),
+		.b			({3'd0, b_hi}),
+		.p			(dsp4_p),
+		.acin		(a_hi_chain),
+		.pcin		(dsp2_p_chain),
+		.acout	(),
+		.pcout	()
 	);
 
 endmodule
+
+//------------------------------------------------------------------------------
+// End-of-File
+//------------------------------------------------------------------------------
diff --git a/src/rtl/pe/artix7/systolic_pe_artix7.v b/src/rtl/pe/artix7/systolic_pe_artix7.v
new file mode 100644
index 0000000..b29f2c0
--- /dev/null
+++ b/src/rtl/pe/artix7/systolic_pe_artix7.v
@@ -0,0 +1,126 @@
+//------------------------------------------------------------------------------
+//
+// systolic_pe_artix7.v
+// -----------------------------------------------------------------------------
+// Hardware (Artix-7 DSP48E1) low-level systolic array processing element.
+//
+// Authors: Pavel Shatov
+//
+// Copyright (c) 2016-2017, NORDUnet A/S
+//
+// 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 systolic_pe_artix7
+	(
+		input					clk,
+		input		[31: 0]	a,
+		input		[31: 0]	b,
+		input		[31: 0]	t,
+		input		[31: 0]	c_in,
+		output	[31: 0]	p,
+		output	[31: 0]	c_out
+	);
+	
+	reg	[31: 0]	t_dly;
+	reg	[31: 0]	c_in_dly;
+	
+	always @(posedge clk) t_dly <= t;
+	always @(posedge clk) c_in_dly <= c_in;
+	
+	wire	[31: 0]	t_c_in_s;
+	wire				t_c_in_c_out;
+	
+	reg				t_c_in_c_out_dly;
+	
+	always @(posedge clk) t_c_in_c_out_dly <= t_c_in_c_out;
+	
+	adder32_artix7 add_t_c_in
+	(
+		.clk		(clk),
+		.ce		(1'b1),
+		.a			(t_dly),
+		.b			(c_in_dly),
+		.c_in		(1'b0),
+		.s			(t_c_in_s),
+		.c_out	(t_c_in_c_out)
+	);
+
+	wire	[63: 0]	a_b;
+	
+	wire	[31: 0]	a_b_lsb = a_b[31: 0];
+	wire	[31: 0]	a_b_msb = a_b[63:32];
+	
+	reg	[31: 0]	a_b_msb_dly;
+	
+	always @(posedge clk) a_b_msb_dly <= a_b_msb;
+	
+	multiplier32_artix7 mul_a_b
+	(
+		.clk	(clk),
+		.a		(a),
+		.b		(b),
+		.p		(a_b)
+	);
+	
+	wire	[31: 0]	add_p_s;
+	wire				add_p_c_out;
+	
+	reg	[31: 0]	add_p_s_dly;
+	
+	always @(posedge clk) add_p_s_dly <= add_p_s;
+	
+	assign p = add_p_s_dly;
+	
+	adder32_artix7 add_p
+	(
+		.clk		(clk),
+		.ce		(1'b1),
+		.a			(a_b_lsb),
+		.b			(t_c_in_s),
+		.c_in		(1'b0),
+		.s			(add_p_s),
+		.c_out	(add_p_c_out)
+	);
+
+	adder32_artix7 add_c_out
+	(
+		.clk		(clk),
+		.ce		(1'b1),
+		.a			(a_b_msb_dly),
+		.b			({{31{1'b0}}, t_c_in_c_out_dly}),
+		.c_in		(add_p_c_out),
+		.s			(c_out),
+		.c_out	()
+	);
+
+endmodule
+
+//------------------------------------------------------------------------------
+// End-of-File
+//------------------------------------------------------------------------------
diff --git a/src/rtl/pe/generic/systolic_pe_generic.v b/src/rtl/pe/generic/systolic_pe_generic.v
new file mode 100644
index 0000000..6c98f44
--- /dev/null
+++ b/src/rtl/pe/generic/systolic_pe_generic.v
@@ -0,0 +1,85 @@
+//======================================================================
+//
+// systolic_pe_generic.v
+// -----------------------------------------------------------------------------
+// Generic low-level systolic array processing element.
+//
+// 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.
+//
+//======================================================================
+
+module systolic_pe_generic
+	(
+		input					clk,
+		input		[31: 0]	a,
+		input		[31: 0]	b,
+		input		[31: 0]	t,
+		input		[31: 0]	c_in,
+		output	[31: 0]	p,
+		output	[31: 0]	c_out
+	);
+
+		//
+		// Customizable Latency
+		//
+	parameter LATENCY = 4;
+		
+		//
+		// Delay Line
+		//
+	reg	[63: 0]	abct[1:LATENCY];
+	
+		//
+		// Outputs
+		//
+	assign p			= abct[LATENCY][31: 0];
+	assign c_out	= abct[LATENCY][63:32];
+
+		//
+		// Sub-products
+		//
+	wire	[63: 0]	ab = {{32{1'b0}}, a}    * {{32{1'b0}}, b};
+	wire	[63: 0]	ct = {{32{1'b0}}, c_in} + {{32{1'b0}}, t};
+
+		//
+		// Delay
+		//
+	integer i;
+	always @(posedge clk)
+		//
+		for (i=1; i<=LATENCY; i=i+1)
+			abct[i] <= (i == 1) ? ab + ct : abct[i-1];
+
+endmodule
+
+//======================================================================
+// End of file
+//======================================================================
diff --git a/src/rtl/pe/modexpa7_adder32.v b/src/rtl/pe/modexpa7_adder32.v
new file mode 100644
index 0000000..ad296b1
--- /dev/null
+++ b/src/rtl/pe/modexpa7_adder32.v
@@ -0,0 +1,76 @@
+//======================================================================
+//
+// modexpa7_adder32.v
+// -----------------------------------------------------------------------------
+// Low-level processing element wrapper (adder).
+//
+// 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.
+//
+//======================================================================
+
+module modexpa7_adder32
+	(
+		input					clk,
+		input					ce,
+		input		[31: 0]	a,
+		input		[31: 0]	b,
+		input					c_in,
+		output	[31: 0]	s,
+		output				c_out
+	);
+	
+	
+		//
+		// Include Primitive Selector
+		//
+	`include "modexpa7_lowlevel_settings.v"
+
+
+		//
+		// Instantiate Vendor/Generic Primitive
+		//
+	`ADDER32_PRIMITIVE adder32_inst
+	(
+		.clk(clk),
+		.ce(ce),
+		.a(a),
+		.b(b),
+		.s(s),
+		.c_in(c_in),
+		.c_out(c_out)
+	);
+
+
+endmodule
+
+//======================================================================
+// End of file
+//======================================================================
diff --git a/src/rtl/pe/modexpa7_lowlevel_settings.v b/src/rtl/pe/modexpa7_lowlevel_settings.v
new file mode 100644
index 0000000..93f5f34
--- /dev/null
+++ b/src/rtl/pe/modexpa7_lowlevel_settings.v
@@ -0,0 +1,15 @@
+//`define USE_VENDOR_PRIMITIVES
+
+`ifdef USE_VENDOR_PRIMITIVES
+
+`define ADDER32_PRIMITIVE			adder32_artix7
+`define SUBTRACTOR32_PRIMITIVE	subtractor32_artix7
+`define SYSTOLIC_PE_PRIMITIVE	systolic_pe_artix7
+
+`else
+
+`define ADDER32_PRIMITIVE			adder32_generic
+`define SUBTRACTOR32_PRIMITIVE	subtractor32_generic
+`define SYSTOLIC_PE_PRIMITIVE	systolic_pe_generic
+
+`endif
diff --git a/src/rtl/pe/modexpa7_subtractor32.v b/src/rtl/pe/modexpa7_subtractor32.v
new file mode 100644
index 0000000..75b9c13
--- /dev/null
+++ b/src/rtl/pe/modexpa7_subtractor32.v
@@ -0,0 +1,76 @@
+//======================================================================
+//
+// modexpa7_subtractor32.v
+// -----------------------------------------------------------------------------
+// Low-level processing element wrapper (subtractor).
+//
+// 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.
+//
+//======================================================================
+
+module modexpa7_subtractor32
+	(
+		input					clk,
+		input					ce,
+		input		[31: 0]	a,
+		input		[31: 0]	b,
+		input					b_in,
+		output	[31: 0]	d,
+		output				b_out
+	);
+	
+	
+		//
+		// Include Primitive Selector
+		//
+	`include "modexpa7_lowlevel_settings.v"
+
+
+		//
+		// Instantiate Vendor/Generic Primitive
+		//
+	`SUBTRACTOR32_PRIMITIVE subtractor32_inst
+	(
+		.clk(clk),
+		.ce(ce),
+		.a(a),
+		.b(b),
+		.d(d),
+		.b_in(b_in),
+		.b_out(b_out)
+	);
+	
+
+endmodule
+
+//======================================================================
+// End of file
+//======================================================================
diff --git a/src/rtl/pe/modexpa7_systolic_pe.v b/src/rtl/pe/modexpa7_systolic_pe.v
new file mode 100644
index 0000000..22e6874
--- /dev/null
+++ b/src/rtl/pe/modexpa7_systolic_pe.v
@@ -0,0 +1,75 @@
+//======================================================================
+//
+// modexpa7_systolic_pe.v
+// -----------------------------------------------------------------------------
+// Low-level processing element wrapper (systolic array processing element).
+//
+// 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.
+//
+//======================================================================
+
+module modexpa7_systolic_pe
+	(
+		input					clk,
+		input		[31: 0]	a,
+		input		[31: 0]	b,
+		input		[31: 0]	t,
+		input		[31: 0]	c_in,
+		output	[31: 0]	p,
+		output	[31: 0]	c_out
+	);
+
+
+		//
+		// Include Primitive Selector
+		//
+	`include "modexpa7_lowlevel_settings.v"
+
+
+		//
+		// Instantiate Vendor/Generic Primitive
+		//
+	`SYSTOLIC_PE_PRIMITIVE systolic_pe_inst
+	(
+		.clk(clk),
+		.a(a),
+		.b(b),
+		.t(t),
+		.c_in(c_in),
+		.p(p),
+		.c_out(c_out)
+	);
+
+endmodule
+
+//======================================================================
+// End of file
+//======================================================================
-- 
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