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dcm_phase.v
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dcm_phase.v
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/*
** -----------------------------------------------------------------------------**
** dcm_phase.v
**
** Copyright (C) 2002 Elphel, Inc
**
** -----------------------------------------------------------------------------**
** This file is part of X353
** X333 is free software - hardware description language (HDL) code.
**
** 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. If not, see <http://www.gnu.org/licenses/>.
** -----------------------------------------------------------------------------**
**
** $Log: dcm_phase.v,v $
** Revision 1.2 2010/05/14 18:48:35 dzhimiev
** 1. added hacts shifts for buffered channels
** 2. set fixed SDRAM spaces
**
*/
`timescale 1 ns / 1 ps
module dcm_phase (
cclk, // command clock for shift
wcmd, // decoded address - enables wclk
cmd, // CPU write data [3:0]
// 0 - nop, just reset status data
// 1 - increase phase shift
// 2 - decrease phase shift
// 3 - reset phase shift to default (preprogrammed in FPGA configuration)
// 4 - incr pahse90
// 8 - decrease phase90
// c - reset phase90
iclk, // DCM input clock
clk_fb, // feed back clock
clk0, // global output clock, phase 0
clk90, // global output clock, phase 90
clk180, // global output clock, phase 180
clk270, // global output clock, phase 270
dcm_phase, // current DCM phase (small steps)
dcm_phase_90,// current DCM quarter (90 degrees steps)
dcm_done, // DCM command done
dcm_status, // DCM status (bit 1 - dcm clkin stopped)
dcm_locked // DCM "Locked" pin
);
parameter NO_SHIFT90=0; //wanted to choose between clk0 BUFGs
input cclk;
input wcmd;
input [ 3:0] cmd;
input iclk;
input clk_fb;
output clk0;
output clk90;
output clk180;
output clk270;
output [8:0] dcm_phase;
output [1:0] dcm_phase_90;
output dcm_done;
output [7:0] dcm_status;
output dcm_locked;
reg dcm_rst=0;
wire dcm_rst_cmd;
reg [2:0] dcm_drst=0;
reg [2:0] dcm_reset_done=0;
wire dcm_done_dcm;
reg dcm_en=0;
reg dcm_incdec=0;
reg [8:0] phase_reg=0;
reg [1:0] phase90_reg=0;
reg dcm_done=0;
assign dcm_phase[8:0] = phase_reg[8:0];
assign dcm_phase_90[1:0] = NO_SHIFT90? 0 : phase90_reg[1:0];
FD i_dcm_rst_cmd(.Q(dcm_rst_cmd), .D((wcmd && (cmd[1:0] == 2'b11)) || (dcm_rst_cmd && !dcm_drst[2])), .C(cclk));
// shift commands are synchronous to the command clock
always @ (posedge cclk) begin
dcm_reset_done[2:0] <= {dcm_reset_done[1] & ~dcm_reset_done[0], dcm_reset_done[0], dcm_rst}; // sync to cclkl end of dcm reset
dcm_en <= wcmd && (cmd[1]!=cmd[0]);
dcm_incdec <= wcmd && cmd[0];
if (wcmd) begin
if (cmd[0] && cmd[1]) phase_reg[8:0] <= 9'h0;
else if (cmd[0]) phase_reg[8:0] <= phase_reg[8:0] +1;
else if (cmd[1]) phase_reg[8:0] <= phase_reg[8:0] -1;
end
if (wcmd) begin
if (cmd[2] && cmd[3]) phase90_reg[1:0] <= 2'h0;
else if (cmd[2]) phase90_reg[1:0] <= phase90_reg[1:0] +1;
else if (cmd[3]) phase90_reg[1:0] <= phase90_reg[1:0] -1;
end
end
// dcm_rst is synchronous to incoming clock
always @ (posedge iclk) begin
dcm_drst[2:0] <= dcm_drst[2]? 3'b0:{dcm_drst[1], dcm_drst[0], dcm_rst_cmd};
dcm_rst <= dcm_drst[0] || dcm_drst[1] || dcm_drst[2] ;
end
// make dcm_done behave as dcm_ready
always @ (posedge cclk)
if (wcmd && |cmd[2:0]) dcm_done <= 0;
else if (dcm_done_dcm || dcm_reset_done[2]) dcm_done <= 1;
/// DCM to compensate sensor delays. Adjustment for data phase - both fine and 90-degrees, hact/vact - 90-degree steps relative to data
DCM_SP #(
.CLKIN_DIVIDE_BY_2("FALSE"), // TRUE/FALSE to enable CLKIN divide by two feature
.CLKIN_PERIOD(10.0), //96Hz
.CLKOUT_PHASE_SHIFT("VARIABLE"),// Specify phase shift of NONE, FIXED or VARIABLE
.CLK_FEEDBACK("1X"), // Specify clock feedback of NONE, 1X or 2X
.DESKEW_ADJUST("SYSTEM_SYNCHRONOUS"), // SOURCE_SYNCHRONOUS, SYSTEM_SYNCHRONOUS or
// an integer from 0 to 15
.DLL_FREQUENCY_MODE("LOW"), // HIGH or LOW frequency mode for DLL
.DUTY_CYCLE_CORRECTION("TRUE"), // Duty cycle correction, TRUE or FALSE
.PHASE_SHIFT(0), // Amount of fixed phase shift from -255 to 255
.STARTUP_WAIT("FALSE") // Delay configuration DONE until DCM LOCK, TRUE/FALSE
) i_dcm_sensor(
.CLKIN (iclk),
.CLKFB (clk_fb),
.RST (dcm_rst),
.PSEN (dcm_en),
.PSINCDEC (dcm_incdec),
.PSCLK (cclk),
.DSSEN (1'b0),
.CLK0 (pre_clk0),
.CLK90 (pre_clk90), // adjust tap
.CLK180 (pre_clk180), // adjust tap
.CLK270 (pre_clk270),
.CLKDV (),
.CLK2X (),
.CLK2X180 (),
.CLKFX (),
.CLKFX180 (),
.STATUS (dcm_status[7:0]),
.LOCKED (dcm_locked),
.PSDONE (dcm_done_dcm)
);
wire pre_clk = phase90_reg[1]? (phase90_reg[0]? pre_clk270:pre_clk180) : (phase90_reg[0]? pre_clk90:pre_clk0);
BUFG i_clk0a (.I(NO_SHIFT90?pre_clk0:pre_clk), .O(clk0));
// BUFG i_clk0b (.I(pre_clk), .O(clk0));
BUFG i_clk90 (.I(pre_clk90), .O(clk90));
BUFG i_clk180 (.I(pre_clk180), .O(clk180));
BUFG i_clk270 (.I(pre_clk270), .O(clk270));
endmodule