/*########################################################################### # Function: Clock and reset generator # # tx_lclk_div4 - Parallel data clock (125Mhz) # # tx_lclk - DDR data clock (500MHz) # # tx_lclk90 - DDR "Clock" for IO (500MHz) # # rx_lclk - High speed RX clock for IO (clkin freq) # # rx_lclk_div4 - Low speed RX clock for logic (75MHz) ############################################################################ */ `include "elink_constants.v" module eclocks (/*AUTOARG*/ // Outputs tx_lclk, tx_lclk90, tx_lclk_div4, rx_lclk, rx_lclk_div4, e_cclk_p, e_cclk_n, elink_reset, e_resetb, // Inputs reset, elink_en, sys_clk, rx_clkin ); parameter RCW = 8; // reset counter width //CCLK PLL parameter SYS_CLK_PERIOD = 10; // (2.5-100ns, set by system) parameter MMCM_VCO_MULT = 12; // 1200MHz parameter CCLK_DIVIDE = 2; // 600MHz //TX (WITH RX FOR NOW...) parameter TXCLK_DIVIDE = 4; // 300MHz default //Input clock, reset, config interface input reset; // async input reset input elink_en; // elink enable (from pin or register) //Main input clocks input sys_clk; // always on input clk cclk/TX MMCM input rx_clkin; // input clk for RX only PLL //TX Clocks output tx_lclk; // tx clock for DDR IO output tx_lclk90; // tx output clock shifted by 90 degrees output tx_lclk_div4; // tx slow clock for logic //RX Clocks output rx_lclk; // rx high speed clock for DDR IO output rx_lclk_div4; // rx slow clock for logic //Epiphany "free running" clock output e_cclk_p, e_cclk_n; //Reset output elink_reset; // reset for elink logic & IO output e_resetb; // reset fpr Epiphany chip //############ //# WIRES //############ //CCLK wire cclk_reset; wire cclk_i; wire cclk_bufio; wire cclk_oddr; //Idelay controller wire idelay_reset; wire idelay_ready; //ignore this? wire idelay_ref_clk_i; wire idelay_ref_clk; //RX wire rx_lclk_i; wire rx_lclk_div4_i; //TX wire tx_lclk_i; wire tx_lclk90_i; wire tx_lckl_div4_i; //MMCM feedback wire mmcm_fb_in; wire mmcm_fb_out; //########################### // RESET STATE MACHINE //########################### reg [RCW:0] reset_counter = 'b0; //works b/c of free running counter! reg heartbeat; reg reset_in; reg reset_sync; wire mmcm_reset; reg [2:0] reset_state; reg mmcm_locked_reg; reg mmcm_locked_sync; //wrap around counter that generates a 1 cycle heartbeat //free running counter... always @ (posedge sys_clk) begin reset_counter[RCW-1:0] <= reset_counter[RCW-1:0]+1'b1; heartbeat <= ~(|reset_counter[RCW-1:0]); end //two clock synchronizer always @ (posedge sys_clk) begin mmcm_locked_reg <= mmcm_locked; mmcm_locked_sync <= mmcm_locked_reg; reset_sync <= (reset | ~elink_en); reset_in <= reset_sync; end `define RESET_ALL 3'b000 `define START_MMCM 3'b001 `define STOP_CCLK 3'b010 `define START_EPIPHANY 3'b011 `define HOLD_IT 3'b100 `define ACTIVE 3'b101 //Reset sequence state machine always @ (posedge sys_clk) if(reset_in) reset_state[2:0] <= `RESET_ALL; else if(heartbeat) case(reset_state[2:0]) `RESET_ALL : reset_state[2:0] <= `START_MMCM; `START_MMCM : if(mmcm_locked_sync) reset_state[2:0] <= `STOP_CCLK; `STOP_CCLK : reset_state[2:0] <= `START_EPIPHANY; `START_EPIPHANY : reset_state[2:0] <= `HOLD_IT; `HOLD_IT : if(mmcm_locked_sync) //TODO: this is not necessary reset_state[2:0] <= `ACTIVE; `ACTIVE: reset_state[2:0] <= `ACTIVE; //stay there until nex reset endcase // case (reset_state[2:0]) //reset PLL during 'reset' and during quiet time around reset edge assign mmcm_reset = (reset_state[2:0]==`RESET_ALL); assign idelay_reset = (reset_state[2:0]==`RESET_ALL) | (reset_state[2:0]==`START_MMCM); assign cclk_reset = (reset_state[2:0]==`STOP_CCLK) | (reset_state[2:0]==`START_EPIPHANY); assign e_resetb = (reset_state[2:0]==`START_EPIPHANY) | (reset_state[2:0]==`HOLD_IT) | (reset_state[2:0]==`ACTIVE); assign elink_reset = (reset_state[2:0]!=`ACTIVE); `ifdef TARGET_XILINX //########################### // MMCM/PLL FOR CCLK AND TX //########################### MMCME2_ADV #( .BANDWIDTH("OPTIMIZED"), .CLKFBOUT_MULT_F(MMCM_VCO_MULT), .CLKFBOUT_PHASE(0.0), .CLKIN1_PERIOD(SYS_CLK_PERIOD), .CLKOUT0_DIVIDE_F(CCLK_DIVIDE), // cclk .CLKOUT1_DIVIDE(TXCLK_DIVIDE), // tx_lclk .CLKOUT2_DIVIDE(TXCLK_DIVIDE), // tx_lclk90 .CLKOUT3_DIVIDE(TXCLK_DIVIDE*4), // tx_lclk_div4 .CLKOUT4_DIVIDE(6), // rx_ref_clk (for idelay) .CLKOUT5_DIVIDE(128), // ?? .CLKOUT6_DIVIDE(128), // ?? .CLKOUT0_DUTY_CYCLE(0.5), .CLKOUT1_DUTY_CYCLE(0.5), .CLKOUT2_DUTY_CYCLE(0.5), .CLKOUT3_DUTY_CYCLE(0.5), .CLKOUT4_DUTY_CYCLE(0.5), .CLKOUT5_DUTY_CYCLE(0.5), .CLKOUT6_DUTY_CYCLE(0.5), .CLKOUT0_PHASE(0.0), .CLKOUT1_PHASE(0.0), .CLKOUT2_PHASE(90.0), .CLKOUT3_PHASE(0.0), .CLKOUT4_PHASE(0.0), .CLKOUT5_PHASE(0.0), .CLKOUT6_PHASE(0.0), .DIVCLK_DIVIDE(1.0), .REF_JITTER1(0.01), .STARTUP_WAIT("FALSE") ) pll_cclk ( .CLKOUT0(cclk_i), .CLKOUT0B(), .CLKOUT1(tx_lclk_i), .CLKOUT1B(), .CLKOUT2(tx_lclk90_i), .CLKOUT2B(), .CLKOUT3(tx_lclk_div4_i), .CLKOUT3B(), .CLKOUT4(idelay_ref_clk_i), .CLKOUT5(), .CLKOUT6(), .PWRDWN(1'b0), .RST(mmcm_reset), //reset .CLKFBIN(mmcm_fb_in), .CLKFBOUT(mmcm_fb_out), //feedback clock .CLKIN1(sys_clk), //input clock .CLKIN2(1'b0), .CLKINSEL(1'b1), .DADDR(7'b0), .DCLK(1'b0), .DEN(1'b0), .DI(16'b0), .DWE(1'b0), .DRDY(), .DO(), .LOCKED(mmcm_locked), //locked indicator .PSCLK(1'b0), .PSEN(1'b0), .PSDONE(), .PSINCDEC(1'b0), .CLKFBSTOPPED(), .CLKINSTOPPED() ); //Tx clock buffers TODO: change to bufr? change port in MMCM in that case!! BUFG tx_lclk_bufg_i(.I(tx_lclk_i), .O(tx_lclk)); BUFG tx_lclk_div4_bufg_i (.I(tx_lclk_div4_i), .O(tx_lclk_div4)); BUFG tx_lclk90_bufg_i (.I(tx_lclk90_i), .O(tx_lclk90)); //Idelay ref clock buffer BUFG idelay_ref_bufg_i(.I(idelay_ref_clk_i), .O(idelay_ref_clk)); //Rx clock buffers BUFR rx_lclk_bufr_i(.I(rx_clkin), .O(rx_lclk)); BUFR #(.BUFR_DIVIDE("4")) rx_lclk_div4_bufr_i ( .I(rx_clkin), .O(rx_lclk_div4), .CE(1'b1), .CLR(1'b0)); //Feedback buffer BUFR mmcm_fb_bufr_i(.I(mmcm_fb_out), .O(mmcm_fb_in)); //########################### // CCLK //########################### //CCLK differential buffer OBUFDS cclk_obuf (.O (e_cclk_p), .OB (e_cclk_n), .I (cclk_oddr) ); //CCLK oddr ODDR #(.DDR_CLK_EDGE ("SAME_EDGE"), .SRTYPE("ASYNC")) oddr_lclk ( .Q (cclk_oddr), .C (cclk_bufio), .CE (1'b1), .D1 (1'b1), .D2 (1'b0), .R (1'b0), .S (1'b0)); //CCLK bufio BUFIO bufio_cclk(.O(cclk_bufio), .I(cclk_i)); //########################### // Idelay controller //########################### (* IODELAY_GROUP = "IDELAY_GROUP" *) // Group name for IDELAYCTRL IDELAYCTRL idelayctrl_inst ( .RDY(idelay_ready), // check ready flag in reset sequence? .REFCLK(idelay_ref_clk),//200MHz clk (78ps tap delay) .RST(idelay_reset)); `endif // `ifdef TARGET_XILINX /* `elsif TARGET_CLEAN clock_divider cclk_divider( // Outputs .clkout (cclk), .clkout90 (), // Inputs .clkin (clkin), .reset (hard_reset), .divcfg (clk_config[7:4]) ) ; clock_divider lclk_divider( // Outputs .clkout (lclk), .clkout90 (lclk90), // Inputs .clkin (clkin), .reset (hard_reset), .divcfg (clk_config[11:8]) ); //This clock is always on! clock_divider lclk_par_divider( // Outputs .clkout (lclk_div4), .clkout90 (), // Inputs .clkin (clkin), .reset (hard_reset), .divcfg (clk_config[11:8] + 4'd2) ); //cclk (hack for sim) //lclk (hack for sim) assign tx_lclk = hard_reset ? clkin : lclk_bp ? pll_bypass[1] : lclk; assign tx_lclk90 = hard_reset ? clkin : lclk_bp ? pll_bypass[2] : lclk90; assign tx_lclk_div4 = hard_reset ? clkin : lclk_bp ? pll_bypass[3] : lclk_div4; `endif reg clkint; initial begin clkint=1'b0; end always #0.5 clkint = ~clkint; */ endmodule // eclocks // Local Variables: // verilog-library-directories:("." "../../common/hdl") // End: /* Copyright (C) 2015 Adapteva, Inc. Contributed by Andreas Olofsson Contributed by Gunnar Hillerstrom This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.This program 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 General Public License for more details. You should have received a copy of the GNU General Public License along with this program (see the file COPYING). If not, see . */