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[/] [amber/] [trunk/] [hw/] [vlog/] [system/] [clocks_resets.v] - Rev 2
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////////////////////////////////////////////////////////////////// // // // Clock and Resets // // // // This file is part of the Amber project // // http://www.opencores.org/project,amber // // // // Description // // Takes in the 200MHx board clock and generates the main // // system clock. For the FPGA this is done with a PLL. // // // // Author(s): // // - Conor Santifort, csantifort.amber@gmail.com // // // ////////////////////////////////////////////////////////////////// // // // Copyright (C) 2010 Authors and OPENCORES.ORG // // // // This source file may be used and distributed without // // restriction provided that this copyright statement is not // // removed from the file and that any derivative work contains // // the original copyright notice and the associated disclaimer. // // // // This source file is free software; you can redistribute it // // and/or modify it under the terms of the GNU Lesser General // // Public License as published by the Free Software Foundation; // // either version 2.1 of the License, or (at your option) any // // later version. // // // // This source is distributed in the hope that it will be // // useful, but WITHOUT ANY WARRANTY; without even the implied // // warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR // // PURPOSE. See the GNU Lesser General Public License for more // // details. // // // // You should have received a copy of the GNU Lesser General // // Public License along with this source; if not, download it // // from http://www.opencores.org/lgpl.shtml // // // ////////////////////////////////////////////////////////////////// // // Clocks and Resets Module // module clocks_resets ( input i_brd_rst, input i_brd_clk_n, input i_brd_clk_p, input i_ddr_calib_done, output o_sys_rst, output o_sys_clk, output o_clk_200 ); wire calib_done_33mhz; wire rst0; assign o_sys_rst = rst0 || !calib_done_33mhz; `ifdef XILINX_FPGA localparam RST_SYNC_NUM = 25; wire pll_locked; wire clkfbout_clkfbin; reg [RST_SYNC_NUM-1:0] rst0_sync_r /* synthesis syn_maxfan = 10 */; reg [RST_SYNC_NUM-1:0] ddr_calib_done_sync_r /* synthesis syn_maxfan = 10 */; wire rst_tmp; wire pll_clk; (* KEEP = "TRUE" *) wire brd_clk_ibufg; IBUFGDS # ( .DIFF_TERM ( "TRUE" ), .IOSTANDARD ( "LVDS_25" )) // SP605 on chip termination of LVDS clock u_ibufgds_brd ( .I ( i_brd_clk_p ), .IB ( i_brd_clk_n ), .O ( brd_clk_ibufg ) ); assign rst0 = rst0_sync_r[RST_SYNC_NUM-1]; assign calib_done_33mhz = ddr_calib_done_sync_r[RST_SYNC_NUM-1]; assign o_clk_200 = brd_clk_ibufg; `ifdef XILINX_SPARTAN6_FPGA // ====================================== // Xilinx Spartan-6 PLL // ====================================== PLL_ADV # ( .BANDWIDTH ( "OPTIMIZED" ), .CLKIN1_PERIOD ( 5 ), .CLKIN2_PERIOD ( 1 ), .CLKOUT0_DIVIDE ( 1 ), .CLKOUT1_DIVIDE ( ), .CLKOUT2_DIVIDE ( `AMBER_CLK_DIVIDER ), // = 800 MHz / LP_CLK_DIVIDER .CLKOUT3_DIVIDE ( 1 ), .CLKOUT4_DIVIDE ( 1 ), .CLKOUT5_DIVIDE ( 1 ), .CLKOUT0_PHASE ( 0.000 ), .CLKOUT1_PHASE ( 0.000 ), .CLKOUT2_PHASE ( 0.000 ), .CLKOUT3_PHASE ( 0.000 ), .CLKOUT4_PHASE ( 0.000 ), .CLKOUT5_PHASE ( 0.000 ), .CLKOUT0_DUTY_CYCLE ( 0.500 ), .CLKOUT1_DUTY_CYCLE ( 0.500 ), .CLKOUT2_DUTY_CYCLE ( 0.500 ), .CLKOUT3_DUTY_CYCLE ( 0.500 ), .CLKOUT4_DUTY_CYCLE ( 0.500 ), .CLKOUT5_DUTY_CYCLE ( 0.500 ), .COMPENSATION ( "INTERNAL" ), .DIVCLK_DIVIDE ( 1 ), .CLKFBOUT_MULT ( 4 ), // 200 MHz clock input, x4 to get 800 MHz MCB .CLKFBOUT_PHASE ( 0.0 ), .REF_JITTER ( 0.005000 ) ) u_pll_adv ( .CLKFBIN ( clkfbout_clkfbin ), .CLKINSEL ( 1'b1 ), .CLKIN1 ( brd_clk_ibufg ), .CLKIN2 ( 1'b0 ), .DADDR ( 5'b0 ), .DCLK ( 1'b0 ), .DEN ( 1'b0 ), .DI ( 16'b0 ), .DWE ( 1'b0 ), .REL ( 1'b0 ), .RST ( i_brd_rst ), .CLKFBDCM ( ), .CLKFBOUT ( clkfbout_clkfbin ), .CLKOUTDCM0 ( ), .CLKOUTDCM1 ( ), .CLKOUTDCM2 ( ), .CLKOUTDCM3 ( ), .CLKOUTDCM4 ( ), .CLKOUTDCM5 ( ), .CLKOUT0 ( ), .CLKOUT1 ( ), .CLKOUT2 ( pll_clk ), .CLKOUT3 ( ), .CLKOUT4 ( ), .CLKOUT5 ( ), .DO ( ), .DRDY ( ), .LOCKED ( pll_locked ) ); `endif `ifdef XILINX_VIRTEX6_FPGA // ====================================== // Xilinx Virtex-6 PLL // ====================================== MMCM_ADV # ( .CLKIN1_PERIOD ( 5 ), // 200 MHz .CLKOUT2_DIVIDE ( `AMBER_CLK_DIVIDER ), .CLKFBOUT_MULT_F ( 5 ) // 200 MHz x 5 = 1000 MHz ) u_pll_adv ( .CLKFBOUT ( clkfbout_clkfbin ), .CLKFBOUTB ( ), .CLKFBSTOPPED ( ), .CLKINSTOPPED ( ), .CLKOUT0 ( ), .CLKOUT0B ( ), .CLKOUT1 ( ), .CLKOUT1B ( ), .CLKOUT2 ( pll_clk ), .CLKOUT2B ( ), .CLKOUT3 ( ), .CLKOUT3B ( ), .CLKOUT4 ( ), .CLKOUT5 ( ), .CLKOUT6 ( ), .DRDY ( ), .LOCKED ( pll_locked ), .PSDONE ( ), .DO ( ), .CLKFBIN ( clkfbout_clkfbin ), .CLKIN1 ( brd_clk_ibufg ), .CLKIN2 ( 1'b0 ), .CLKINSEL ( 1'b1 ), .DCLK ( 1'b0 ), .DEN ( 1'b0 ), .DWE ( 1'b0 ), .PSCLK ( 1'd0 ), .PSEN ( 1'd0 ), .PSINCDEC ( 1'd0 ), .PWRDWN ( 1'd0 ), .RST ( i_brd_rst ), .DI ( 16'b0 ), .DADDR ( 7'b0 ) ); `endif BUFG u_bufg_sys_clk ( .O ( o_sys_clk ), .I ( pll_clk ) ); // ====================================== // Synchronous reset generation // ====================================== assign rst_tmp = i_brd_rst | ~pll_locked; // synthesis attribute max_fanout of rst0_sync_r is 10 always @(posedge o_sys_clk or posedge rst_tmp) if (rst_tmp) rst0_sync_r <= {RST_SYNC_NUM{1'b1}}; else // logical left shift by one (pads with 0) rst0_sync_r <= rst0_sync_r << 1; always @(posedge o_sys_clk or posedge rst_tmp) if (rst_tmp) ddr_calib_done_sync_r <= {RST_SYNC_NUM{1'b0}}; else ddr_calib_done_sync_r <= {ddr_calib_done_sync_r[RST_SYNC_NUM-2:0], i_ddr_calib_done}; `endif `ifndef XILINX_FPGA localparam [7:0] FULL_COUNT = `AMBER_CLK_DIVIDER / 4; localparam [7:0] HALF_COUNT = FULL_COUNT / 2; // e.g. Divide clock by 6 to get 33MHz reg [7:0] clk_div_count; initial begin clk_div_count <= FULL_COUNT - 1'd3; forever @ (posedge i_brd_clk_p) if ( clk_div_count == ( FULL_COUNT - 1'd1 ) ) clk_div_count <= 8'h0; else clk_div_count <= clk_div_count + 1'd1; end assign o_sys_clk = clk_div_count < HALF_COUNT; assign rst0 = i_brd_rst; assign calib_done_33mhz = 1'd1; assign o_clk_200 = i_brd_clk_p; `endif endmodule
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