Add first draft of functional SB_MAC16 model

Signed-off-by: Clifford Wolf <clifford@clifford.at>

1 files changed, 175 insertions, 53 deletions

diff --git a/techlibs/ice40/cells_sim.v b/techlibs/ice40/cells_sim.v
index 38ed45981..4a92fccdf 100644
--- a/techlibs/ice40/cells_sim.v
+++ b/techlibs/ice40/cells_sim.v
@@ -886,59 +886,6 @@ module SB_WARMBOOT (
 );
 endmodule
 
-// UltraPlus feature cells
-(* blackbox *)
-module SB_MAC16 (
-	input CLK,
-	input CE,
-	input [15:0] C,
-	input [15:0] A,
-	input [15:0] B,
-	input [15:0] D,
-	input AHOLD,
-	input BHOLD,
-	input CHOLD,
-	input DHOLD,
-	input IRSTTOP,
-	input IRSTBOT,
-	input ORSTTOP,
-	input ORSTBOT,
-	input OLOADTOP,
-	input OLOADBOT,
-	input ADDSUBTOP,
-	input ADDSUBBOT,
-	input OHOLDTOP,
-	input OHOLDBOT,
-	input CI,
-	input ACCUMCI,
-	input SIGNEXTIN,
-	output [31:0] O,
-	output CO,
-	output ACCUMCO,
-	output SIGNEXTOUT
-);
-parameter NEG_TRIGGER = 1'b0;
-parameter C_REG = 1'b0;
-parameter A_REG = 1'b0;
-parameter B_REG = 1'b0;
-parameter D_REG = 1'b0;
-parameter TOP_8x8_MULT_REG = 1'b0;
-parameter BOT_8x8_MULT_REG = 1'b0;
-parameter PIPELINE_16x16_MULT_REG1 = 1'b0;
-parameter PIPELINE_16x16_MULT_REG2 = 1'b0;
-parameter TOPOUTPUT_SELECT =  2'b00;
-parameter TOPADDSUB_LOWERINPUT = 2'b00;
-parameter TOPADDSUB_UPPERINPUT = 1'b0;
-parameter TOPADDSUB_CARRYSELECT = 2'b00;
-parameter BOTOUTPUT_SELECT =  2'b00;
-parameter BOTADDSUB_LOWERINPUT = 2'b00;
-parameter BOTADDSUB_UPPERINPUT = 1'b0;
-parameter BOTADDSUB_CARRYSELECT = 2'b00;
-parameter MODE_8x8 = 1'b0;
-parameter A_SIGNED = 1'b0;
-parameter B_SIGNED = 1'b0;
-endmodule
-
 module SB_SPRAM256KA (
 	input [13:0] ADDRESS,
 	input [15:0] DATAIN,
@@ -1273,3 +1220,178 @@ module SB_IO_OD (
 	endgenerate
 `endif
 endmodule
+
+module SB_MAC16 (
+	input CLK, CE,
+	input [15:0] C, A, B, D,
+	input AHOLD, BHOLD, CHOLD, DHOLD,
+	input IRSTTOP, IRSTBOT,
+	input ORSTTOP, ORSTBOT,
+	input OLOADTOP, OLOADBOT,
+	input ADDSUBTOP, ADDSUBBOT,
+	input OHOLDTOP, OHOLDBOT,
+	input CI, ACCUMCI, SIGNEXTIN,
+	output [31:0] O,
+	output CO, ACCUMCO, SIGNEXTOUT
+);
+	parameter [0:0] NEG_TRIGGER = 0;
+	parameter [0:0] C_REG = 0;
+	parameter [0:0] A_REG = 0;
+	parameter [0:0] B_REG = 0;
+	parameter [0:0] D_REG = 0;
+	parameter [0:0] TOP_8x8_MULT_REG = 0;
+	parameter [0:0] BOT_8x8_MULT_REG = 0;
+	parameter [0:0] PIPELINE_16x16_MULT_REG1 = 0;
+	parameter [0:0] PIPELINE_16x16_MULT_REG2 = 0;
+	parameter [1:0] TOPOUTPUT_SELECT = 0;
+	parameter [1:0] TOPADDSUB_LOWERINPUT = 0;
+	parameter [0:0] TOPADDSUB_UPPERINPUT = 0;
+	parameter [1:0] TOPADDSUB_CARRYSELECT = 0;
+	parameter [1:0] BOTOUTPUT_SELECT = 0;
+	parameter [1:0] BOTADDSUB_LOWERINPUT = 0;
+	parameter [0:0] BOTADDSUB_UPPERINPUT = 0;
+	parameter [1:0] BOTADDSUB_CARRYSELECT = 0;
+	parameter [0:0] MODE_8x8 = 0;
+	parameter [0:0] A_SIGNED = 0;
+	parameter [0:0] B_SIGNED = 0;
+
+	wire clock = CLK ^ NEG_TRIGGER;
+
+	// internal wires, compare Figure on page 133 of ICE Technology Library 3.0 and Fig 2 on page 2 of Lattice TN1295-DSP
+	// http://www.latticesemi.com/~/media/LatticeSemi/Documents/TechnicalBriefs/SBTICETechnologyLibrary201608.pdf
+	// https://www.latticesemi.com/-/media/LatticeSemi/Documents/ApplicationNotes/AD/DSPFunctionUsageGuideforICE40Devices.ashx
+	wire [15:0] iA, iB, iC, iD;
+	wire [15:0] iF, iJ, iK, iG;
+	wire [31:0] iL, iH;
+	wire [15:0] iW, iX, iP, iQ;
+	wire [15:0] iY, iZ, iR, iS;
+	wire HCI, LCI, LCO;
+
+	// Regs C and A
+	reg [15:0] rC, rA;
+	always @(posedge clock, posedge IRSTTOP) begin
+		if (IRSTTOP) begin
+			rC <= 0;
+			rA <= 0;
+		end else if (CE) begin
+			if (!CHOLD) rC <= C;
+			if (!AHOLD) rA <= A;
+		end
+	end
+	assign iC = C_REG ? rC : C;
+	assign iA = A_REG ? rA : A;
+
+	// Regs B and D
+	reg [15:0] rB, rD;
+	always @(posedge clock, posedge IRSTTOP) begin
+		if (IRSTBOT) begin
+			rB <= 0;
+			rD <= 0;
+		end else if (CE) begin
+			if (!BHOLD) rB <= B;
+			if (!DHOLD) rD <= D;
+		end
+	end
+	assign iB = B_REG ? rB : B;
+	assign iD = D_REG ? rD : D;
+
+	// Multiplier Stage
+	wire [15:0] p_Ah_Bh, p_Al_Bh, p_Ah_Bl, p_Al_Bl;
+	wire [15:0] Ah, Al, Bh, Bl;
+	assign Ah = A_SIGNED ? {{8{iA[15]}}, iA[15: 8]} : iA[15: 8];
+	assign Al = A_SIGNED ? {{8{iA[ 7]}}, iA[ 7: 0]} : iA[15: 8];
+	assign Bh = B_SIGNED ? {{8{iB[15]}}, iB[15: 8]} : iB[15: 8];
+	assign Bl = B_SIGNED ? {{8{iB[ 7]}}, iB[ 7: 0]} : iB[15: 8];
+	assign p_Ah_Bh = Ah * Bh;
+	assign p_Al_Bh = Al * Bh;
+	assign p_Ah_Bl = Ah * Bl;
+	assign p_Al_Bl = Al * Bl;
+
+	// Regs F and J
+	reg [15:0] rF, rJ;
+	always @(posedge clock, posedge IRSTTOP) begin
+		if (IRSTTOP) begin
+			rF <= 0;
+			rJ <= 0;
+		end else if (CE) begin
+			rF <= p_Ah_Bh;
+			if (!MODE_8x8) rJ <= p_Al_Bh;
+		end
+	end
+	assign iF = TOP_8x8_MULT_REG ? rF : p_Ah_Bh;
+	assign iJ = PIPELINE_16x16_MULT_REG1 ? rJ : p_Al_Bh;
+
+	// Regs K and G
+	reg [15:0] rK, rG;
+	always @(posedge clock, posedge IRSTBOT) begin
+		if (IRSTBOT) begin
+			rK <= 0;
+			rG <= 0;
+		end else if (CE) begin
+			if (!MODE_8x8) rK <= p_Ah_Bl;
+			rG <= p_Al_Bl;
+		end
+	end
+	assign iK = PIPELINE_16x16_MULT_REG1 ? rK : p_Ah_Bl;
+	assign iG = BOT_8x8_MULT_REG ? rG : p_Al_Bl;
+
+	// Adder Stage
+	reg [31:0] P;
+	always @* begin
+		P = iG[7:0];
+		P = P + (iG[15:8] + iK[7:0]) << 8;
+		P = P + (iK[15:8] + iJ[7:0]) << 16;
+		P = P + (iJ[15:8] + iF[7:0]) << 24;
+	end
+	assign iL = P;
+
+	// Reg H
+	reg [15:0] rH;
+	always @(posedge clock, posedge IRSTBOT) begin
+		if (IRSTBOT) begin
+			rH <= 0;
+		end else if (CE) begin
+			if (!MODE_8x8) rH <= iL;
+		end
+	end
+	assign iH = PIPELINE_16x16_MULT_REG2 ? rH : iL;
+
+	// Hi Output Stage
+	wire [15:0] XW, Oh;
+	reg [15:0] rQ;
+	assign iW = TOPADDSUB_UPPERINPUT ? iC : iQ[31:16];
+	assign iX = (TOPADDSUB_LOWERINPUT == 0) ? iA : (TOPADDSUB_LOWERINPUT == 1) ? iF : (TOPADDSUB_LOWERINPUT == 2) ? iH[31:16] : {16{iZ[15]}};
+	assign {ACCUMCO, XW} = iX + (iW ^ {16{ADDSUBTOP}}) + HCI;
+	assign CO = ACCUMCO ^ ADDSUBTOP;
+	assign iP = OLOADTOP ? iC : XW ^ {16{ADDSUBTOP}};
+	always @(posedge clock, posedge ORSTTOP) begin
+		if (ORSTTOP) begin
+			rQ <= 0;
+		end else if (CE) begin
+			if (!OHOLDTOP) rQ <= iP;
+		end
+	end
+	assign iQ = rQ;
+	assign Oh = (TOPOUTPUT_SELECT == 0) ? iP : (TOPOUTPUT_SELECT == 1) ? iQ : (TOPOUTPUT_SELECT == 2) ? iF : iH[31:16];
+	assign HCI = (TOPADDSUB_CARRYSELECT == 0) ? 1'b0 : (TOPADDSUB_CARRYSELECT == 1) ? 1'b1 : (TOPADDSUB_CARRYSELECT == 2) ? LCO : LCO ^ ADDSUBBOT;
+	assign SIGNEXTOUT = iX[15];
+
+	// Lo Output Stage
+	wire [15:0] YZ, Ol;
+	reg [15:0] rS;
+	assign iY = BOTADDSUB_UPPERINPUT ? iD : iQ[15:0];
+	assign iZ = (BOTADDSUB_LOWERINPUT == 0) ? iB : (BOTADDSUB_LOWERINPUT == 1) ? iG : (BOTADDSUB_LOWERINPUT == 2) ? iH[15:0] : {16{SIGNEXTIN}};
+	assign {LCO, YZ} = iZ + (iY ^ {16{ADDSUBBOT}}) + LCI;
+	assign iR = OLOADBOT ? iD : YZ ^ {16{ADDSUBBOT}};
+	always @(posedge clock, posedge ORSTBOT) begin
+		if (ORSTBOT) begin
+			rS <= 0;
+		end else if (CE) begin
+			if (!OHOLDTOP) rS <= iR;
+		end
+	end
+	assign iS = rS;
+	assign Ol = (BOTOUTPUT_SELECT == 0) ? iR : (BOTOUTPUT_SELECT == 1) ? iS : (BOTOUTPUT_SELECT == 2) ? iG : iH[15:0];
+	assign LCI = (BOTADDSUB_CARRYSELECT == 0) ? 1'b0 : (BOTADDSUB_CARRYSELECT == 1) ? 1'b1 : (BOTADDSUB_CARRYSELECT == 2) ? ACCUMCI : CI;
+	assign O = {Oh, Ol};
+endmodule