//
// Copyright 2011-2013 Ettus Research LLC
//
//! X300/X310 digital down-conversion chain
module ddc_chain_x300
#(
parameter BASE = 0,
parameter DSPNO = 0,
parameter WIDTH = 24
)
(input clk, input rst, input clr,
input set_stb, input [7:0] set_addr, input [31:0] set_data,
// From RX frontend
input [WIDTH-1:0] rx_fe_i,
input [WIDTH-1:0] rx_fe_q,
// To RX control
output [31:0] sample,
input run,
output strobe,
output [31:0] debug
);
localparam cwidth = 25;
localparam zwidth = 24;
wire [31:0] phase_inc;
reg [31:0] phase;
wire [17:0] scale_factor;
wire [cwidth-1:0] i_cordic, q_cordic;
wire [WIDTH-1:0] i_cordic_clip, q_cordic_clip;
wire [WIDTH-1:0] i_cic, q_cic;
wire [46:0] i_hb1, q_hb1;
wire [46:0] i_hb2, q_hb2;
wire [47:0] i_hb3, q_hb3;
wire strobe_cic, strobe_hb1, strobe_hb2, strobe_hb3;
wire [7:0] cic_decim_rate;
reg [WIDTH-1:0] rx_fe_i_mux, rx_fe_q_mux;
wire realmode;
wire swap_iq;
wire [1:0] hb_rate;
wire [2:0] enable_hb = { hb_rate == 2'b11, hb_rate[1] == 1'b1, hb_rate != 2'b00 };
wire reload_go, reload_we1, reload_we2, reload_we3, reload_ld1, reload_ld2, reload_ld3;
wire [17:0] coef_din;
setting_reg #(.my_addr(BASE+0)) sr_0
(.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
.in(set_data),.out(phase_inc),.changed());
setting_reg #(.my_addr(BASE+1), .width(18)) sr_1
(.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
.in(set_data),.out(scale_factor),.changed());
setting_reg #(.my_addr(BASE+2), .width(10)) sr_2
(.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
.in(set_data),.out({hb_rate, cic_decim_rate}),.changed());
setting_reg #(.my_addr(BASE+3), .width(2)) sr_3
(.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
.in(set_data),.out({realmode,swap_iq}),.changed());
setting_reg #(.my_addr(BASE+4), .width(24)) sr_4
(.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
.in(set_data),.out({reload_ld3,reload_we3,reload_ld2,reload_we2,reload_ld1,reload_we1,coef_din}),.changed(reload_go));
// MUX so we can do realmode signals on either input
always @(posedge clk)
if(swap_iq)
begin
rx_fe_i_mux <= rx_fe_q;
rx_fe_q_mux <= realmode ? 0 : rx_fe_i;
end
else
begin
rx_fe_i_mux <= rx_fe_i;
rx_fe_q_mux <= realmode ? 0 : rx_fe_q;
end
// NCO
always @(posedge clk)
if(rst)
phase <= 0;
else if(~run)
phase <= 0;
else
phase <= phase + phase_inc;
//sign extension of cordic input
wire [cwidth-1:0] to_cordic_i, to_cordic_q;
sign_extend #(.bits_in(WIDTH), .bits_out(cwidth)) sign_extend_cordic_i (.in(rx_fe_i_mux), .out(to_cordic_i));
sign_extend #(.bits_in(WIDTH), .bits_out(cwidth)) sign_extend_cordic_q (.in(rx_fe_q_mux), .out(to_cordic_q));
// CORDIC 24-bit I/O
cordic_z24 #(.bitwidth(cwidth))
cordic(.clock(clk), .reset(rst), .enable(run),
.xi(to_cordic_i),. yi(to_cordic_q), .zi(phase[31:32-zwidth]),
.xo(i_cordic),.yo(q_cordic),.zo() );
clip_reg #(.bits_in(cwidth), .bits_out(WIDTH)) clip_cordic_i
(.clk(clk), .in(i_cordic), .strobe_in(1'b1), .out(i_cordic_clip));
clip_reg #(.bits_in(cwidth), .bits_out(WIDTH)) clip_cordic_q
(.clk(clk), .in(q_cordic), .strobe_in(1'b1), .out(q_cordic_clip));
// CIC decimator 24 bit I/O
cic_strober cic_strober(.clock(clk),.reset(rst),.enable(run),.rate(cic_decim_rate),
.strobe_fast(1'b1),.strobe_slow(strobe_cic) );
cic_decim #(.bw(WIDTH))
decim_i (.clock(clk),.reset(rst),.enable(run),
.rate(cic_decim_rate),.strobe_in(1'b1),.strobe_out(strobe_cic),
.signal_in(i_cordic_clip),.signal_out(i_cic));
cic_decim #(.bw(WIDTH))
decim_q (.clock(clk),.reset(rst),.enable(run),
.rate(cic_decim_rate),.strobe_in(1'b1),.strobe_out(strobe_cic),
.signal_in(q_cordic_clip),.signal_out(q_cic));
// Halfbands
wire nd1, nd2, nd3;
wire rfd1, rfd2, rfd3;
wire rdy1, rdy2, rdy3;
wire data_valid1, data_valid2, data_valid3;
localparam HB1_SCALE = 18;
localparam HB2_SCALE = 18;
localparam HB3_SCALE = 18;
assign strobe_hb1 = data_valid1;
assign strobe_hb2 = data_valid2;
assign strobe_hb3 = data_valid3;
assign nd1 = strobe_cic;
assign nd2 = strobe_hb1;
assign nd3 = strobe_hb2;
hbdec1 hbdec1
(.clk(clk), // input clk
.sclr(rst), // input sclr
.ce(enable_hb[0]), // input ce
.coef_ld(reload_go & reload_ld1), // input coef_ld
.coef_we(reload_go & reload_we1), // input coef_we
.coef_din(coef_din), // input [17 : 0] coef_din
.rfd(rfd1), // output rfd
.nd(nd1), // input nd
.din_1(i_cic), // input [23 : 0] din_1
.din_2(q_cic), // input [23 : 0] din_2
.rdy(rdy1), // output rdy
.data_valid(data_valid1), // output data_valid
.dout_1(i_hb1), // output [46 : 0] dout_1
.dout_2(q_hb1)); // output [46 : 0] dout_2
hbdec2 hbdec2
(.clk(clk), // input clk
.sclr(rst), // input sclr
.ce(enable_hb[1]), // input ce
.coef_ld(reload_go & reload_ld2), // input coef_ld
.coef_we(reload_go & reload_we2), // input coef_we
.coef_din(coef_din), // input [17 : 0] coef_din
.rfd(rfd2), // output rfd
.nd(nd2), // input nd
.din_1(i_hb1[23+HB1_SCALE:HB1_SCALE]), // input [23 : 0] din_1
.din_2(q_hb1[23+HB1_SCALE:HB1_SCALE]), // input [23 : 0] din_2
.rdy(rdy2), // output rdy
.data_valid(data_valid2), // output data_valid
.dout_1(i_hb2), // output [46 : 0] dout_1
.dout_2(q_hb2)); // output [46 : 0] dout_2
hbdec3 hbdec3
(.clk(clk), // input clk
.sclr(rst), // input sclr
.ce(enable_hb[2]), // input ce
.coef_ld(reload_go & reload_ld3), // input coef_ld
.coef_we(reload_go & reload_we3), // input coef_we
.coef_din(coef_din), // input [17 : 0] coef_din
.rfd(rfd3), // output rfd
.nd(strobe_hb2), // input nd
.din_1(i_hb2[23+HB2_SCALE:HB2_SCALE]), // input [23 : 0] din_1
.din_2(q_hb2[23+HB2_SCALE:HB2_SCALE]), // input [23 : 0] din_2
.rdy(rdy3), // output rdy
.data_valid(data_valid3), // output data_valid
.dout_1(i_hb3), // output [47 : 0] dout_1
.dout_2(q_hb3)); // output [47 : 0] dout_2
reg [23:0] i_unscaled, q_unscaled;
reg strobe_unscaled;
always @(posedge clk)
case(hb_rate)
2'd0 :
begin
strobe_unscaled <= strobe_cic;
i_unscaled <= i_cic[23:0];
q_unscaled <= q_cic[23:0];
end
2'd1 :
begin
strobe_unscaled <= strobe_hb1;
i_unscaled <= i_hb1[23+HB1_SCALE:HB1_SCALE];
q_unscaled <= q_hb1[23+HB1_SCALE:HB1_SCALE];
end
2'd2 :
begin
strobe_unscaled <= strobe_hb2;
i_unscaled <= i_hb2[23+HB2_SCALE:HB2_SCALE];
q_unscaled <= q_hb2[23+HB2_SCALE:HB2_SCALE];
end
2'd3 :
begin
strobe_unscaled <= strobe_hb3;
i_unscaled <= i_hb3[23+HB3_SCALE:HB3_SCALE];
q_unscaled <= q_hb3[23+HB3_SCALE:HB3_SCALE];
end
endcase // case (hb_rate)
wire [42:0] i_scaled, q_scaled;
wire [23:0] i_clip, q_clip;
reg strobe_scaled;
wire strobe_clip;
MULT_MACRO #(.DEVICE("7SERIES"), // Target Device: "VIRTEX5", "VIRTEX6", "SPARTAN6","7SERIES"
.LATENCY(1), // Desired clock cycle latency, 0-4
.WIDTH_A(25), // Multiplier A-input bus width, 1-25
.WIDTH_B(18)) // Multiplier B-input bus width, 1-18
SCALE_I (.P(i_scaled), // Multiplier output bus, width determined by WIDTH_P parameter
.A({i_unscaled[23],i_unscaled}), // Multiplier input A bus, width determined by WIDTH_A parameter
.B(scale_factor), // Multiplier input B bus, width determined by WIDTH_B parameter
.CE(strobe_unscaled), // 1-bit active high input clock enable
.CLK(clk), // 1-bit positive edge clock input
.RST(rst)); // 1-bit input active high reset
MULT_MACRO #(.DEVICE("7SERIES"), // Target Device: "VIRTEX5", "VIRTEX6", "SPARTAN6","7SERIES"
.LATENCY(1), // Desired clock cycle latency, 0-4
.WIDTH_A(25), // Multiplier A-input bus width, 1-25
.WIDTH_B(18)) // Multiplier B-input bus width, 1-18
SCALE_Q (.P(q_scaled), // Multiplier output bus, width determined by WIDTH_P parameter
.A({q_unscaled[23],q_unscaled}), // Multiplier input A bus, width determined by WIDTH_A parameter
.B(scale_factor), // Multiplier input B bus, width determined by WIDTH_B parameter
.CE(strobe_unscaled), // 1-bit active high input clock enable
.CLK(clk), // 1-bit positive edge clock input
.RST(rst)); // 1-bit input active high reset
always @(posedge clk) strobe_scaled <= strobe_unscaled;
clip_reg #(.bits_in(29), .bits_out(24), .STROBED(1)) clip_i
(.clk(clk), .in(i_scaled[42:14]), .strobe_in(strobe_scaled), .out(i_clip), .strobe_out(strobe_clip));
clip_reg #(.bits_in(29), .bits_out(24), .STROBED(1)) clip_q
(.clk(clk), .in(q_scaled[42:14]), .strobe_in(strobe_scaled), .out(q_clip), .strobe_out());
round_sd #(.WIDTH_IN(24), .WIDTH_OUT(16)) round_i
(.clk(clk), .reset(rst), .in(i_clip), .strobe_in(strobe_clip), .out(sample[31:16]), .strobe_out(strobe));
round_sd #(.WIDTH_IN(24), .WIDTH_OUT(16)) round_q
(.clk(clk), .reset(rst), .in(q_clip), .strobe_in(strobe_clip), .out(sample[15:0]), .strobe_out());
endmodule // ddc_chain