From c43b0c4b49235da5aee658413a2a6f880aff09b0 Mon Sep 17 00:00:00 2001 From: David Shah Date: Tue, 6 Aug 2019 18:47:18 +0100 Subject: [PATCH] [wip] DSP48E1 sim model improvements Signed-off-by: David Shah --- techlibs/xilinx/cells_sim.v | 143 ++++++++++++++++++++++++++++++------ 1 file changed, 120 insertions(+), 23 deletions(-) diff --git a/techlibs/xilinx/cells_sim.v b/techlibs/xilinx/cells_sim.v index 9437a057b..bc8a2d8f0 100644 --- a/techlibs/xilinx/cells_sim.v +++ b/techlibs/xilinx/cells_sim.v @@ -494,19 +494,35 @@ module DSP48E1 ( `endif end + wire signed [29:0] A_muxed; + wire signed [17:0] B_muxed; + + generate + if (A_INPUT == "CASCADE") assign A_muxed = ACIN; + else assign A_muxed = A; + + if (B_INPUT == "CASCADE") assign B_muxed = BCIN; + else assign B_muxed = B; + endgenerate + reg signed [29:0] Ar1, Ar2; reg signed [24:0] Dr; reg signed [17:0] Br1, Br2; - reg signed [47:0] Pr; + reg signed [47:0] Cr; reg [4:0] INMODEr; + reg [6:0] OPMODEr; + reg [3:0] ALUMODEr; + reg [2:0] CARRYINSELr; + generate + // Configurable A register if (AREG == 2) begin always @(posedge CLK) if (RSTA) begin Ar1 <= 30'b0; Ar2 <= 30'b0; end else begin - if (CEA1) Ar1 <= A; + if (CEA1) Ar1 <= A_muxed; if (CEA2) Ar2 <= Ar1; end end else if (AREG == 1) begin @@ -515,21 +531,22 @@ module DSP48E1 ( Ar1 <= 30'b0; Ar2 <= 30'b0; end else begin - if (CEA1) Ar1 <= A; - if (CEA2) Ar2 <= A; + if (CEA1) Ar1 <= A_muxed; + if (CEA2) Ar2 <= A_muxed; end end else begin - always @* Ar1 <= A; - always @* Ar2 <= A; + always @* Ar1 <= A_muxed; + always @* Ar2 <= A_muxed; end + // Configurable A register if (BREG == 2) begin always @(posedge CLK) if (RSTB) begin Br1 <= 18'b0; Br2 <= 18'b0; end else begin - if (CEB1) Br1 <= B; + if (CEB1) Br1 <= B_muxed; if (CEB2) Br2 <= Br1; end end else if (AREG == 1) begin @@ -538,21 +555,41 @@ module DSP48E1 ( Br1 <= 18'b0; Br2 <= 18'b0; end else begin - if (CEB1) Br1 <= B; - if (CEB2) Br2 <= B; + if (CEB1) Br1 <= B_muxed; + if (CEB2) Br2 <= B_muxed; end end else begin - always @* Br1 <= B; - always @* Br2 <= B; + always @* Br1 <= B_muxed; + always @* Br2 <= B_muxed; end + // C and D registers + if (CREG == 1) begin always @(posedge CLK) if (RSTC) Cr <= 48'b0; else if (CEC) Cr <= D; end + else always @* Cr <= C; + if (DREG == 1) begin always @(posedge CLK) if (RSTD) Dr <= 25'b0; else if (CED) Dr <= D; end else always @* Dr <= D; + // Control registers if (INMODEREG == 1) begin always @(posedge CLK) if (RSTINMODE) INMODEr <= 5'b0; else if (CEINMODE) INMODEr <= INMODE; end else always @* INMODEr <= INMODE; + if (OPMODEREG == 1) begin always @(posedge CLK) if (RSTCTRL) OPMODEr <= 7'b0; else if (CECTRL) OPMODEr <= OPMODE; end + else always @* OPMODEr <= OPMODE; + if (ALUMODEREG == 1) begin always @(posedge CLK) if (RSTALUMODE) ALUMODEr <= 4'b0; else if (CEALUMODE) ALUMODEr <= ALUMODE; end + else always @* ALUMODEr <= ALUMODE; + if (CARRYINSELREG == 1) begin always @(posedge CLK) if (RSTCTRL) CARRYINSELr <= 3'b0; else if (CECTRL) CARRYINSELr <= CARRYINSEL; end + else always @* CARRYINSELr <= CARRYINSEL; + endgenerate + + // A and B cascsde + generate + if (ACASCREG == 1 && AREG == 2) assign ACOUT = Ar1; + else assign ACOUT = Ar2; + if (BCASCREG == 1 && BREG == 2) assign BCOUT = Br1; + else assign BCOUT = Br2; endgenerate + // A/D input selection and pre-adder wire signed [29:0] Ar12_muxed = INMODEr[0] ? Ar1 : Ar2; wire signed [24:0] Ar12_gated = INMODEr[1] ? 25'b0 : Ar12_muxed; wire signed [24:0] Dr_gated = INMODEr[2] ? Dr : 25'b0; @@ -564,31 +601,91 @@ module DSP48E1 ( else always @* ADr <= AD_result; endgenerate + // 25x18 multiplier wire signed [24:0] A_MULT; - wire signed [24:0] B_MULT = INMODEr[4] ? Br1 : Br2; + wire signed [17:0] B_MULT = INMODEr[4] ? Br1 : Br2; generate if (USE_DPORT == "TRUE") assign A_MULT = ADr; else assign A_MULT = Ar12_gated; endgenerate + wire signed [42:0] M = A_MULT * B_MULT; + reg signed [42:0] Mr; + + // Multiplier result register + generate + if (MREG == 1) begin always @(posedge CLK) if (RSTM) Mr <= 43'b0; else if (CEM) Mr <= M; end + else always @* Mr <= M; + endgenerate + + // X, Y and Z ALU inputs + reg signed [47:0] X, Y, Z; + + always @* begin + // X multiplexer + case (OPMODEr[1:0]) + 2'b00: X = 48'b0; + 2'b01: X = $signed(M); +`ifdef __ICARUS__ + if (OPMODEr[3:2] != 2'b01) $fatal(1, "OPMODEr[3:2] must be 2'b01 when OPMODEr[1:0] is 2'b01"); +`endif + 2'b10: X = P; +`ifdef __ICARUS__ + if (PREG != 1) $fatal(1, "PREG must be 1 when OPMODEr[1:0] is 2'b10"); +`endif + 2'b11: X = $signed({Ar2, Br2}); + default: X = 48'bx; + endcase + + // Y multiplexer + case (OPMODEr[3:2]) + 2'b00: Y = 48'b0; + 2'b01: Y = 48'b0; // FIXME: more accurate partial product modelling? +`ifdef __ICARUS__ + if (OPMODEr[1:0] != 2'b01) $fatal(1, "OPMODEr[1:0] must be 2'b01 when OPMODEr[3:2] is 2'b01"); +`endif + 2'b10: Y = {48{1'b1}}; + 2'b11: Y = C; + default: Y = 48'bx; + endcase + + // Z multiplexer + case (OPMODEr[6:4]) + 3'b000: Z = 48'b0; + 3'b001: Z = PCIN; + 3'b010: Z = P; +`ifdef __ICARUS__ + if (PREG != 1) $fatal(1, "PREG must be 1 when OPMODEr[6:4] i0s 3'b010"); +`endif + 3'b011: Z = C; + 3'b100: Z = P; +`ifdef __ICARUS__ + if (PREG != 1) $fatal(1, "PREG must be 1 when OPMODEr[6:4] is 3'b100"); + if (OPMODEr[3:0] != 4'b1000) $fatal(1, "OPMODEr[3:0] must be 4'b1000 when OPMODEr[6:4] i0s 3'b100"); +`endif + 3'b101: Z = $signed(PCIN[47:17]); + 3'b110: Z = $signed(P[47:17]); + default: Z = 48'bx; + endcase + end + + wire alu_cin = 1'b0; // FIXME* + + wire [47:0] Z_muxinv = ALUMODEr[0] ? ~Z : Z; + wire [47:0] xor_xyz = X ^ Y ^ Z_muxinv; + wire [47:0] maj_xyz = (X & Y) | (X & Z) | (X & Y); + + + always @* begin - Pr <= {48{1'bx}}; `ifdef __ICARUS__ - if (INMODE != 4'b0000) $fatal(1, "Unsupported INMODE value"); - if (ALUMODE != 4'b0000) $fatal(1, "Unsupported ALUMODE value"); - if (OPMODE != 7'b000101) $fatal(1, "Unsupported OPMODE value"); if (CARRYINSEL != 3'b000) $fatal(1, "Unsupported CARRYINSEL value"); - if (ACIN != 30'b0) $fatal(1, "Unsupported ACIN value"); - if (BCIN != 18'b0) $fatal(1, "Unsupported BCIN value"); - if (PCIN != 48'b0) $fatal(1, "Unsupported PCIN value"); - if (CARRYIN != 1'b0) $fatal(1, "Unsupported CARRYIN value"); `endif - Pr[42:0] <= A_MULT * B_MULT; end generate - if (PREG == 1) begin always @(posedge CLK) if (RSTP) P <= 48'b0; else if (CEP) P <= Pr; end - else always @* P <= Pr; + if (PREG == 1) begin always @(posedge CLK) if (RSTP) P <= 48'b0; else if (CEP) P <= Mr; end + else always @* P <= Mr; endgenerate endmodule -- 2.30.2