/* * yosys -- Yosys Open SYnthesis Suite * * Copyright (C) 2012 Clifford Wolf * * Permission to use, copy, modify, and/or distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. * */ // See Xilinx UG953 and UG474 for a description of the cell types below. // http://www.xilinx.com/support/documentation/user_guides/ug474_7Series_CLB.pdf // http://www.xilinx.com/support/documentation/sw_manuals/xilinx2014_4/ug953-vivado-7series-libraries.pdf module VCC(output P); assign P = 1; endmodule module GND(output G); assign G = 0; endmodule module IBUF(output O, input I); parameter IOSTANDARD = "default"; parameter IBUF_LOW_PWR = 0; assign O = I; endmodule module OBUF(output O, input I); parameter IOSTANDARD = "default"; parameter DRIVE = 12; parameter SLEW = "SLOW"; assign O = I; endmodule module BUFG(output O, input I); assign O = I; endmodule module BUFGCTRL( output O, input I0, input I1, input S0, input S1, input CE0, input CE1, input IGNORE0, input IGNORE1); parameter [0:0] INIT_OUT = 1'b0; parameter PRESELECT_I0 = "FALSE"; parameter PRESELECT_I1 = "FALSE"; parameter [0:0] IS_CE0_INVERTED = 1'b0; parameter [0:0] IS_CE1_INVERTED = 1'b0; parameter [0:0] IS_S0_INVERTED = 1'b0; parameter [0:0] IS_S1_INVERTED = 1'b0; parameter [0:0] IS_IGNORE0_INVERTED = 1'b0; parameter [0:0] IS_IGNORE1_INVERTED = 1'b0; wire I0_internal = ((CE0 ^ IS_CE0_INVERTED) ? I0 : INIT_OUT); wire I1_internal = ((CE1 ^ IS_CE1_INVERTED) ? I1 : INIT_OUT); wire S0_true = (S0 ^ IS_S0_INVERTED); wire S1_true = (S1 ^ IS_S1_INVERTED); assign O = S0_true ? I0_internal : (S1_true ? I1_internal : INIT_OUT); endmodule module BUFHCE(output O, input I, input CE); parameter [0:0] INIT_OUT = 1'b0; parameter CE_TYPE = "SYNC"; parameter [0:0] IS_CE_INVERTED = 1'b0; assign O = ((CE ^ IS_CE_INVERTED) ? I : INIT_OUT); endmodule // module OBUFT(output O, input I, T); // assign O = T ? 1'bz : I; // endmodule // module IOBUF(inout IO, output O, input I, T); // assign O = IO, IO = T ? 1'bz : I; // endmodule module INV(output O, input I); assign O = !I; endmodule module LUT1(output O, input I0); parameter [1:0] INIT = 0; assign O = I0 ? INIT[1] : INIT[0]; endmodule module LUT2(output O, input I0, I1); parameter [3:0] INIT = 0; wire [ 1: 0] s1 = I1 ? INIT[ 3: 2] : INIT[ 1: 0]; assign O = I0 ? s1[1] : s1[0]; endmodule module LUT3(output O, input I0, I1, I2); parameter [7:0] INIT = 0; wire [ 3: 0] s2 = I2 ? INIT[ 7: 4] : INIT[ 3: 0]; wire [ 1: 0] s1 = I1 ? s2[ 3: 2] : s2[ 1: 0]; assign O = I0 ? s1[1] : s1[0]; endmodule module LUT4(output O, input I0, I1, I2, I3); parameter [15:0] INIT = 0; wire [ 7: 0] s3 = I3 ? INIT[15: 8] : INIT[ 7: 0]; wire [ 3: 0] s2 = I2 ? s3[ 7: 4] : s3[ 3: 0]; wire [ 1: 0] s1 = I1 ? s2[ 3: 2] : s2[ 1: 0]; assign O = I0 ? s1[1] : s1[0]; endmodule module LUT5(output O, input I0, I1, I2, I3, I4); parameter [31:0] INIT = 0; wire [15: 0] s4 = I4 ? INIT[31:16] : INIT[15: 0]; wire [ 7: 0] s3 = I3 ? s4[15: 8] : s4[ 7: 0]; wire [ 3: 0] s2 = I2 ? s3[ 7: 4] : s3[ 3: 0]; wire [ 1: 0] s1 = I1 ? s2[ 3: 2] : s2[ 1: 0]; assign O = I0 ? s1[1] : s1[0]; endmodule module LUT6(output O, input I0, I1, I2, I3, I4, I5); parameter [63:0] INIT = 0; wire [31: 0] s5 = I5 ? INIT[63:32] : INIT[31: 0]; wire [15: 0] s4 = I4 ? s5[31:16] : s5[15: 0]; wire [ 7: 0] s3 = I3 ? s4[15: 8] : s4[ 7: 0]; wire [ 3: 0] s2 = I2 ? s3[ 7: 4] : s3[ 3: 0]; wire [ 1: 0] s1 = I1 ? s2[ 3: 2] : s2[ 1: 0]; assign O = I0 ? s1[1] : s1[0]; endmodule module LUT6_2(output O6, output O5, input I0, I1, I2, I3, I4, I5); parameter [63:0] INIT = 0; wire [31: 0] s5 = I5 ? INIT[63:32] : INIT[31: 0]; wire [15: 0] s4 = I4 ? s5[31:16] : s5[15: 0]; wire [ 7: 0] s3 = I3 ? s4[15: 8] : s4[ 7: 0]; wire [ 3: 0] s2 = I2 ? s3[ 7: 4] : s3[ 3: 0]; wire [ 1: 0] s1 = I1 ? s2[ 3: 2] : s2[ 1: 0]; assign O6 = I0 ? s1[1] : s1[0]; wire [15: 0] s5_4 = I4 ? INIT[31:16] : INIT[15: 0]; wire [ 7: 0] s5_3 = I3 ? s5_4[15: 8] : s5_4[ 7: 0]; wire [ 3: 0] s5_2 = I2 ? s5_3[ 7: 4] : s5_3[ 3: 0]; wire [ 1: 0] s5_1 = I1 ? s5_2[ 3: 2] : s5_2[ 1: 0]; assign O5 = I0 ? s5_1[1] : s5_1[0]; endmodule module MUXCY(output O, input CI, DI, S); assign O = S ? CI : DI; endmodule (* abc_box_id = 1, lib_whitebox *) module MUXF7(output O, input I0, I1, S); assign O = S ? I1 : I0; endmodule (* abc_box_id = 2, lib_whitebox *) module MUXF8(output O, input I0, I1, S); assign O = S ? I1 : I0; endmodule `ifdef _ABC (* abc_box_id = 3, lib_whitebox *) module \$__XILINX_MUXF78 (output O, input I0, I1, I2, I3, S0, S1); assign O = S1 ? (S0 ? I3 : I2) : (S0 ? I1 : I0); endmodule `endif module XORCY(output O, input CI, LI); assign O = CI ^ LI; endmodule (* abc_box_id = 4, abc_carry="CI,CO", lib_whitebox *) module CARRY4(output [3:0] CO, O, input CI, CYINIT, input [3:0] DI, S); assign O = S ^ {CO[2:0], CI | CYINIT}; assign CO[0] = S[0] ? CI | CYINIT : DI[0]; assign CO[1] = S[1] ? CO[0] : DI[1]; assign CO[2] = S[2] ? CO[1] : DI[2]; assign CO[3] = S[3] ? CO[2] : DI[3]; endmodule `ifdef _EXPLICIT_CARRY module CARRY0(output CO_CHAIN, CO_FABRIC, O, input CI, CI_INIT, DI, S); parameter CYINIT_FABRIC = 0; wire CI_COMBINE; if(CYINIT_FABRIC) begin assign CI_COMBINE = CI_INIT; end else begin assign CI_COMBINE = CI; end assign CO_CHAIN = S ? CI_COMBINE : DI; assign CO_FABRIC = S ? CI_COMBINE : DI; assign O = S ^ CI_COMBINE; endmodule module CARRY(output CO_CHAIN, CO_FABRIC, O, input CI, DI, S); assign CO_CHAIN = S ? CI : DI; assign CO_FABRIC = S ? CI : DI; assign O = S ^ CI; endmodule `endif module FDRE (output reg Q, input C, CE, D, R); parameter [0:0] INIT = 1'b0; parameter [0:0] IS_C_INVERTED = 1'b0; parameter [0:0] IS_D_INVERTED = 1'b0; parameter [0:0] IS_R_INVERTED = 1'b0; initial Q <= INIT; generate case (|IS_C_INVERTED) 1'b0: always @(posedge C) if (R == !IS_R_INVERTED) Q <= 1'b0; else if (CE) Q <= D ^ IS_D_INVERTED; 1'b1: always @(negedge C) if (R == !IS_R_INVERTED) Q <= 1'b0; else if (CE) Q <= D ^ IS_D_INVERTED; endcase endgenerate endmodule module FDSE (output reg Q, input C, CE, D, S); parameter [0:0] INIT = 1'b1; parameter [0:0] IS_C_INVERTED = 1'b0; parameter [0:0] IS_D_INVERTED = 1'b0; parameter [0:0] IS_S_INVERTED = 1'b0; initial Q <= INIT; generate case (|IS_C_INVERTED) 1'b0: always @(posedge C) if (S == !IS_S_INVERTED) Q <= 1'b1; else if (CE) Q <= D ^ IS_D_INVERTED; 1'b1: always @(negedge C) if (S == !IS_S_INVERTED) Q <= 1'b1; else if (CE) Q <= D ^ IS_D_INVERTED; endcase endgenerate endmodule module FDCE (output reg Q, input C, CE, D, CLR); parameter [0:0] INIT = 1'b0; parameter [0:0] IS_C_INVERTED = 1'b0; parameter [0:0] IS_D_INVERTED = 1'b0; parameter [0:0] IS_CLR_INVERTED = 1'b0; initial Q <= INIT; generate case ({|IS_C_INVERTED, |IS_CLR_INVERTED}) 2'b00: always @(posedge C, posedge CLR) if ( CLR) Q <= 1'b0; else if (CE) Q <= D ^ IS_D_INVERTED; 2'b01: always @(posedge C, negedge CLR) if (!CLR) Q <= 1'b0; else if (CE) Q <= D ^ IS_D_INVERTED; 2'b10: always @(negedge C, posedge CLR) if ( CLR) Q <= 1'b0; else if (CE) Q <= D ^ IS_D_INVERTED; 2'b11: always @(negedge C, negedge CLR) if (!CLR) Q <= 1'b0; else if (CE) Q <= D ^ IS_D_INVERTED; endcase endgenerate endmodule module FDPE (output reg Q, input C, CE, D, PRE); parameter [0:0] INIT = 1'b1; parameter [0:0] IS_C_INVERTED = 1'b0; parameter [0:0] IS_D_INVERTED = 1'b0; parameter [0:0] IS_PRE_INVERTED = 1'b0; initial Q <= INIT; generate case ({|IS_C_INVERTED, |IS_PRE_INVERTED}) 2'b00: always @(posedge C, posedge PRE) if ( PRE) Q <= 1'b1; else if (CE) Q <= D ^ IS_D_INVERTED; 2'b01: always @(posedge C, negedge PRE) if (!PRE) Q <= 1'b1; else if (CE) Q <= D ^ IS_D_INVERTED; 2'b10: always @(negedge C, posedge PRE) if ( PRE) Q <= 1'b1; else if (CE) Q <= D ^ IS_D_INVERTED; 2'b11: always @(negedge C, negedge PRE) if (!PRE) Q <= 1'b1; else if (CE) Q <= D ^ IS_D_INVERTED; endcase endgenerate endmodule module FDRE_1 (output reg Q, input C, CE, D, R); parameter [0:0] INIT = 1'b0; initial Q <= INIT; always @(negedge C) if (R) Q <= 1'b0; else if(CE) Q <= D; endmodule module FDSE_1 (output reg Q, input C, CE, D, S); parameter [0:0] INIT = 1'b1; initial Q <= INIT; always @(negedge C) if (S) Q <= 1'b1; else if(CE) Q <= D; endmodule module FDCE_1 (output reg Q, input C, CE, D, CLR); parameter [0:0] INIT = 1'b0; initial Q <= INIT; always @(negedge C, posedge CLR) if (CLR) Q <= 1'b0; else if (CE) Q <= D; endmodule module FDPE_1 (output reg Q, input C, CE, D, PRE); parameter [0:0] INIT = 1'b1; initial Q <= INIT; always @(negedge C, posedge PRE) if (PRE) Q <= 1'b1; else if (CE) Q <= D; endmodule (* abc_box_id = 5, abc_scc_break="D,WE" *) module RAM32X1D ( output DPO, SPO, input D, WCLK, WE, input A0, A1, A2, A3, A4, input DPRA0, DPRA1, DPRA2, DPRA3, DPRA4 ); parameter INIT = 32'h0; parameter IS_WCLK_INVERTED = 1'b0; wire [4:0] a = {A4, A3, A2, A1, A0}; wire [4:0] dpra = {DPRA4, DPRA3, DPRA2, DPRA1, DPRA0}; reg [31:0] mem = INIT; assign SPO = mem[a]; assign DPO = mem[dpra]; wire clk = WCLK ^ IS_WCLK_INVERTED; always @(posedge clk) if (WE) mem[a] <= D; endmodule (* abc_box_id = 6, abc_scc_break="D,WE" *) module RAM64X1D ( output DPO, SPO, input D, WCLK, WE, input A0, A1, A2, A3, A4, A5, input DPRA0, DPRA1, DPRA2, DPRA3, DPRA4, DPRA5 ); parameter INIT = 64'h0; parameter IS_WCLK_INVERTED = 1'b0; wire [5:0] a = {A5, A4, A3, A2, A1, A0}; wire [5:0] dpra = {DPRA5, DPRA4, DPRA3, DPRA2, DPRA1, DPRA0}; reg [63:0] mem = INIT; assign SPO = mem[a]; assign DPO = mem[dpra]; wire clk = WCLK ^ IS_WCLK_INVERTED; always @(posedge clk) if (WE) mem[a] <= D; endmodule (* abc_box_id = 7, abc_scc_break="D,WE" *) module RAM128X1D ( output DPO, SPO, input D, WCLK, WE, input [6:0] A, DPRA ); parameter INIT = 128'h0; parameter IS_WCLK_INVERTED = 1'b0; reg [127:0] mem = INIT; assign SPO = mem[A]; assign DPO = mem[DPRA]; wire clk = WCLK ^ IS_WCLK_INVERTED; always @(posedge clk) if (WE) mem[A] <= D; endmodule module SRL16E ( output Q, input A0, A1, A2, A3, CE, CLK, D ); parameter [15:0] INIT = 16'h0000; parameter [0:0] IS_CLK_INVERTED = 1'b0; reg [15:0] r = INIT; assign Q = r[{A3,A2,A1,A0}]; generate if (IS_CLK_INVERTED) begin always @(negedge CLK) if (CE) r <= { r[14:0], D }; end else always @(posedge CLK) if (CE) r <= { r[14:0], D }; endgenerate endmodule module SRLC32E ( output Q, output Q31, input [4:0] A, input CE, CLK, D ); parameter [31:0] INIT = 32'h00000000; parameter [0:0] IS_CLK_INVERTED = 1'b0; reg [31:0] r = INIT; assign Q31 = r[31]; assign Q = r[A]; generate if (IS_CLK_INVERTED) begin always @(negedge CLK) if (CE) r <= { r[30:0], D }; end else always @(posedge CLK) if (CE) r <= { r[30:0], D }; endgenerate endmodule module DSP48E1 ( output [29:0] ACOUT, output [17:0] BCOUT, output CARRYCASCOUT, output [3:0] CARRYOUT, output MULTSIGNOUT, output OVERFLOW, output reg signed [47:0] P, output PATTERNBDETECT, output PATTERNDETECT, output [47:0] PCOUT, output UNDERFLOW, input signed [29:0] A, input [29:0] ACIN, input [3:0] ALUMODE, input signed [17:0] B, input [17:0] BCIN, input [47:0] C, input CARRYCASCIN, input CARRYIN, input [2:0] CARRYINSEL, input CEA1, input CEA2, input CEAD, input CEALUMODE, input CEB1, input CEB2, input CEC, input CECARRYIN, input CECTRL, input CED, input CEINMODE, input CEM, input CEP, input CLK, input [24:0] D, input [4:0] INMODE, input MULTSIGNIN, input [6:0] OPMODE, input [47:0] PCIN, input RSTA, input RSTALLCARRYIN, input RSTALUMODE, input RSTB, input RSTC, input RSTCTRL, input RSTD, input RSTINMODE, input RSTM, input RSTP ); parameter integer ACASCREG = 1; parameter integer ADREG = 1; parameter integer ALUMODEREG = 1; parameter integer AREG = 1; parameter AUTORESET_PATDET = "NO_RESET"; parameter A_INPUT = "DIRECT"; parameter integer BCASCREG = 1; parameter integer BREG = 1; parameter B_INPUT = "DIRECT"; parameter integer CARRYINREG = 1; parameter integer CARRYINSELREG = 1; parameter integer CREG = 1; parameter integer DREG = 1; parameter integer INMODEREG = 1; parameter integer MREG = 1; parameter integer OPMODEREG = 1; parameter integer PREG = 1; parameter SEL_MASK = "MASK"; parameter SEL_PATTERN = "PATTERN"; parameter USE_DPORT = "FALSE"; parameter USE_MULT = "MULTIPLY"; parameter USE_PATTERN_DETECT = "NO_PATDET"; parameter USE_SIMD = "ONE48"; parameter [47:0] MASK = 48'h3FFFFFFFFFFF; parameter [47:0] PATTERN = 48'h000000000000; parameter [3:0] IS_ALUMODE_INVERTED = 4'b0; parameter [0:0] IS_CARRYIN_INVERTED = 1'b0; parameter [0:0] IS_CLK_INVERTED = 1'b0; parameter [4:0] IS_INMODE_INVERTED = 5'b0; parameter [6:0] IS_OPMODE_INVERTED = 7'b0; initial begin `ifdef __ICARUS__ if (ACASCREG != 0) $fatal(1, "Unsupported ACASCREG value"); if (ADREG != 0) $fatal(1, "Unsupported ADREG value"); if (ALUMODEREG != 0) $fatal(1, "Unsupported ALUMODEREG value"); if (AREG == 2) $fatal(1, "Unsupported AREG value"); if (AUTORESET_PATDET != "NO_RESET") $fatal(1, "Unsupported AUTORESET_PATDET value"); if (A_INPUT != "DIRECT") $fatal(1, "Unsupported A_INPUT value"); if (BCASCREG != 0) $fatal(1, "Unsupported BCASCREG value"); if (BREG == 2) $fatal(1, "Unsupported BREG value"); if (B_INPUT != "DIRECT") $fatal(1, "Unsupported B_INPUT value"); if (CARRYINREG != 0) $fatal(1, "Unsupported CARRYINREG value"); if (CARRYINSELREG != 0) $fatal(1, "Unsupported CARRYINSELREG value"); if (CREG != 0) $fatal(1, "Unsupported CREG value"); if (DREG != 0) $fatal(1, "Unsupported DREG value"); if (INMODEREG != 0) $fatal(1, "Unsupported INMODEREG value"); if (MREG != 0) $fatal(1, "Unsupported MREG value"); if (OPMODEREG != 0) $fatal(1, "Unsupported OPMODEREG value"); //if (PREG != 0) $fatal(1, "Unsupported PREG value"); if (SEL_MASK != "MASK") $fatal(1, "Unsupported SEL_MASK value"); if (SEL_PATTERN != "PATTERN") $fatal(1, "Unsupported SEL_PATTERN value"); if (USE_DPORT != "FALSE") $fatal(1, "Unsupported USE_DPORT value"); if (USE_MULT != "MULTIPLY") $fatal(1, "Unsupported USE_MULT value"); if (USE_PATTERN_DETECT != "NO_PATDET") $fatal(1, "Unsupported USE_PATTERN_DETECT value"); if (USE_SIMD != "ONE48") $fatal(1, "Unsupported USE_SIMD value"); if (IS_ALUMODE_INVERTED != 4'b0) $fatal(1, "Unsupported IS_ALUMODE_INVERTED value"); if (IS_CARRYIN_INVERTED != 1'b0) $fatal(1, "Unsupported IS_CARRYIN_INVERTED value"); if (IS_CLK_INVERTED != 1'b0) $fatal(1, "Unsupported IS_CLK_INVERTED value"); if (IS_INMODE_INVERTED != 5'b0) $fatal(1, "Unsupported IS_INMODE_INVERTED value"); if (IS_OPMODE_INVERTED != 7'b0) $fatal(1, "Unsupported IS_OPMODE_INVERTED value"); `endif end reg signed [29:0] Ar1, Ar2; reg signed [24:0] Dr; reg signed [17:0] Br1, Br2; reg signed [47:0] Pr; reg [4:0] INMODEr; generate if (AREG == 2) begin always @(posedge CLK) if (RSTA) begin Ar1 <= 30'b0; Ar2 <= 30'b0; end else begin if (CEA1) Ar1 <= A; if (CEA2) Ar2 <= Ar1; end end else if (AREG == 1) begin always @(posedge CLK) if (RSTA) begin Ar1 <= 30'b0; Ar2 <= 30'b0; end else begin if (CEA1) Ar1 <= A; if (CEA2) Ar2 <= A; end end else begin always @* Ar1 <= A; always @* Ar2 <= A; end if (BREG == 2) begin always @(posedge CLK) if (RSTB) begin Br1 <= 18'b0; Br2 <= 18'b0; end else begin if (CEB1) Br1 <= B; if (CEB2) Br2 <= Br1; end end else if (AREG == 1) begin always @(posedge CLK) if (RSTB) begin Br1 <= 18'b0; Br2 <= 18'b0; end else begin if (CEB1) Br1 <= B; if (CEB2) Br2 <= B; end end else begin always @* Br1 <= B; always @* Br2 <= B; end if (DREG == 1) begin always @(posedge CLK) if (RSTD) Dr <= 25'b0; else if (CED) Dr <= D; end else always @* Dr <= D; if (INMODEREG == 1) begin always @(posedge CLK) if (RSTINMODE) INMODEr <= 5'b0; else if (CEINMODE) INMODEr <= INMODE; end else always @* INMODEr <= INMODE; endgenerate 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; wire signed [24:0] AD_result = INMODEr[3] ? (Dr_gated - Ar12_gated) : (Dr_gated + Ar12_gated); reg signed [24:0] ADr; generate if (ADREG == 1) begin always @(posedge CLK) if (RSTD) ADr <= 25'b0; else if (CEAD) ADr <= AD_result; end else always @* ADr <= AD_result; endgenerate wire signed [24:0] A_MULT; wire signed [24:0] B_MULT = INMODEr[4] ? Br1 : Br2; generate if (USE_DPORT == "TRUE") assign A_MULT = ADr; else assign A_MULT = Ar12_gated; endgenerate 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; endgenerate endmodule