2 `define DSP_CORE_TX_BASE 128
6 input set_stb, input [7:0] set_addr, input [31:0] set_data,
8 output reg [15:0] dac_a,
9 output reg [15:0] dac_b,
18 wire [15:0] i, q, scale_i, scale_q;
19 wire [31:0] phase_inc;
21 wire [7:0] interp_rate;
23 wire enable_hb1, enable_hb2;
25 setting_reg #(.my_addr(`DSP_CORE_TX_BASE+0)) sr_0
26 (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
27 .in(set_data),.out(phase_inc),.changed());
29 setting_reg #(.my_addr(`DSP_CORE_TX_BASE+1)) sr_1
30 (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
31 .in(set_data),.out({scale_i,scale_q}),.changed());
33 setting_reg #(.my_addr(`DSP_CORE_TX_BASE+2)) sr_2
34 (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
35 .in(set_data),.out({enable_hb1, enable_hb2, interp_rate}),.changed());
37 // Strobes are all now delayed by 1 cycle for timing reasons
38 wire strobe_cic_pre, strobe_hb1_pre, strobe_hb2_pre;
43 cic_strober #(.WIDTH(8))
44 cic_strober(.clock(clk),.reset(rst),.enable(run),.rate(interp_rate),
45 .strobe_fast(1),.strobe_slow(strobe_cic_pre) );
46 cic_strober #(.WIDTH(2))
47 hb2_strober(.clock(clk),.reset(rst),.enable(run),.rate(enable_hb2 ? 2 : 1),
48 .strobe_fast(strobe_cic_pre),.strobe_slow(strobe_hb2_pre) );
49 cic_strober #(.WIDTH(2))
50 hb1_strober(.clock(clk),.reset(rst),.enable(run),.rate(enable_hb1 ? 2 : 1),
51 .strobe_fast(strobe_hb2_pre),.strobe_slow(strobe_hb1_pre) );
53 always @(posedge clk) strobe_hb1 <= strobe_hb1_pre;
54 always @(posedge clk) strobe_hb2 <= strobe_hb2_pre;
55 always @(posedge clk) strobe_cic <= strobe_cic_pre;
62 phase <= phase + phase_inc;
64 wire signed [17:0] da, db;
65 wire signed [35:0] prod_i, prod_q;
67 wire [17:0] bb_i = {sample[31:16],2'b0};
68 wire [17:0] bb_q = {sample[15:0],2'b0};
69 wire [17:0] i_interp, q_interp;
71 wire [17:0] hb1_i, hb1_q, hb2_i, hb2_q;
73 wire [7:0] cpo = enable_hb2 ? ({interp_rate,1'b0}) : interp_rate;
74 // Note that max CIC rate is 128, which would give an overflow on cpo if enable_hb2 is true,
75 // but the default case inside hb_interp handles this
77 hb_interp #(.IWIDTH(18),.OWIDTH(18),.ACCWIDTH(24)) hb_interp_i
78 (.clk(clk),.rst(rst),.bypass(~enable_hb1),.cpo(cpo),.stb_in(strobe_hb1),.data_in(bb_i),.stb_out(strobe_hb2),.data_out(hb1_i));
79 hb_interp #(.IWIDTH(18),.OWIDTH(18),.ACCWIDTH(24)) hb_interp_q
80 (.clk(clk),.rst(rst),.bypass(~enable_hb1),.cpo(cpo),.stb_in(strobe_hb1),.data_in(bb_q),.stb_out(strobe_hb2),.data_out(hb1_q));
82 small_hb_int #(.WIDTH(18)) small_hb_interp_i
83 (.clk(clk),.rst(rst),.bypass(~enable_hb2),.stb_in(strobe_hb2),.data_in(hb1_i),
84 .output_rate(interp_rate),.stb_out(strobe_cic),.data_out(hb2_i));
85 small_hb_int #(.WIDTH(18)) small_hb_interp_q
86 (.clk(clk),.rst(rst),.bypass(~enable_hb2),.stb_in(strobe_hb2),.data_in(hb1_q),
87 .output_rate(interp_rate),.stb_out(strobe_cic),.data_out(hb2_q));
89 cic_interp #(.bw(18),.N(4),.log2_of_max_rate(7))
90 cic_interp_i(.clock(clk),.reset(rst),.enable(run),.rate(interp_rate),
91 .strobe_in(strobe_cic),.strobe_out(1),
92 .signal_in(hb2_i),.signal_out(i_interp));
94 cic_interp #(.bw(18),.N(4),.log2_of_max_rate(7))
95 cic_interp_q(.clock(clk),.reset(rst),.enable(run),.rate(interp_rate),
96 .strobe_in(strobe_cic),.strobe_out(1),
97 .signal_in(hb2_q),.signal_out(q_interp));
99 assign strobe = strobe_hb1;
101 cordic #(.bitwidth(18),.zwidth(16))
102 cordic(.clock(clk), .reset(rst), .enable(run),
103 .xi(i_interp),.yi(q_interp),.zi(phase[31:16]),
104 .xo(da),.yo(db),.zo() );
106 MULT18X18S MULT18X18S_inst
107 (.P(prod_i), // 36-bit multiplier output
108 .A(da), // 18-bit multiplier input
109 .B({{2{scale_i[15]}},scale_i}), // 18-bit multiplier input
110 .C(clk), // Clock input
111 .CE(1), // Clock enable input
112 .R(rst) // Synchronous reset input
115 MULT18X18S MULT18X18S_inst_2
116 (.P(prod_q), // 36-bit multiplier output
117 .A(db), // 18-bit multiplier input
118 .B({{2{scale_q[15]}},scale_q}), // 18-bit multiplier input
119 .C(clk), // Clock input
120 .CE(1), // Clock enable input
121 .R(rst) // Synchronous reset input
124 always @(posedge clk)
125 dac_a <= prod_i[28:13];
127 always @(posedge clk)
128 dac_b <= prod_q[28:13];
130 assign debug = {strobe_cic, strobe_hb1, strobe_hb2,run};
132 endmodule // dsp_core