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author | Josh Blum <josh@joshknows.com> | 2010-01-22 11:56:55 -0800 |
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committer | Josh Blum <josh@joshknows.com> | 2010-01-22 11:56:55 -0800 |
commit | 7bf8a6df381a667134b55701993c6770d32bc76b (patch) | |
tree | 4a298fb5450f7277b5aaf5210740ae18f818c9aa /usrp2/sdr_lib/dsp_core_tx.v | |
parent | 8f2c33eab9396185df259639082b7d1618585973 (diff) | |
download | uhd-7bf8a6df381a667134b55701993c6770d32bc76b.tar.gz uhd-7bf8a6df381a667134b55701993c6770d32bc76b.tar.bz2 uhd-7bf8a6df381a667134b55701993c6770d32bc76b.zip |
Moved usrp2 fpga files into usrp2 subdir.
Diffstat (limited to 'usrp2/sdr_lib/dsp_core_tx.v')
-rw-r--r-- | usrp2/sdr_lib/dsp_core_tx.v | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/usrp2/sdr_lib/dsp_core_tx.v b/usrp2/sdr_lib/dsp_core_tx.v new file mode 100644 index 000000000..346d65ced --- /dev/null +++ b/usrp2/sdr_lib/dsp_core_tx.v @@ -0,0 +1,152 @@ + +`define DSP_CORE_TX_BASE 128 + +module dsp_core_tx + (input clk, input rst, + input set_stb, input [7:0] set_addr, input [31:0] set_data, + + output reg [15:0] dac_a, + output reg [15:0] dac_b, + + // To tx_control + input [31:0] sample, + input run, + output strobe, + output [31:0] debug + ); + + wire [15:0] i, q, scale_i, scale_q; + wire [31:0] phase_inc; + reg [31:0] phase; + wire [7:0] interp_rate; + wire [3:0] dacmux_a, dacmux_b; + wire enable_hb1, enable_hb2; + + setting_reg #(.my_addr(`DSP_CORE_TX_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(`DSP_CORE_TX_BASE+1)) sr_1 + (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr), + .in(set_data),.out({scale_i,scale_q}),.changed()); + + setting_reg #(.my_addr(`DSP_CORE_TX_BASE+2)) sr_2 + (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr), + .in(set_data),.out({enable_hb1, enable_hb2, interp_rate}),.changed()); + + setting_reg #(.my_addr(`DSP_CORE_TX_BASE+4)) sr_4 + (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr), + .in(set_data),.out({dacmux_b,dacmux_a}),.changed()); + + // Strobes are all now delayed by 1 cycle for timing reasons + wire strobe_cic_pre, strobe_hb1_pre, strobe_hb2_pre; + reg strobe_cic = 1; + reg strobe_hb1 = 1; + reg strobe_hb2 = 1; + + cic_strober #(.WIDTH(8)) + cic_strober(.clock(clk),.reset(rst),.enable(run),.rate(interp_rate), + .strobe_fast(1),.strobe_slow(strobe_cic_pre) ); + cic_strober #(.WIDTH(2)) + hb2_strober(.clock(clk),.reset(rst),.enable(run),.rate(enable_hb2 ? 2 : 1), + .strobe_fast(strobe_cic_pre),.strobe_slow(strobe_hb2_pre) ); + cic_strober #(.WIDTH(2)) + hb1_strober(.clock(clk),.reset(rst),.enable(run),.rate(enable_hb1 ? 2 : 1), + .strobe_fast(strobe_hb2_pre),.strobe_slow(strobe_hb1_pre) ); + + always @(posedge clk) strobe_hb1 <= strobe_hb1_pre; + always @(posedge clk) strobe_hb2 <= strobe_hb2_pre; + always @(posedge clk) strobe_cic <= strobe_cic_pre; + + // NCO + always @(posedge clk) + if(rst) + phase <= 0; + else if(~run) + phase <= 0; + else + phase <= phase + phase_inc; + + wire signed [17:0] da, db; + wire signed [35:0] prod_i, prod_q; + + wire [17:0] bb_i = {sample[31:16],2'b0}; + wire [17:0] bb_q = {sample[15:0],2'b0}; + wire [17:0] i_interp, q_interp; + + wire [17:0] hb1_i, hb1_q, hb2_i, hb2_q; + + wire [7:0] cpo = enable_hb2 ? ({interp_rate,1'b0}) : interp_rate; + // Note that max CIC rate is 128, which would give an overflow on cpo if enable_hb2 is true, + // but the default case inside hb_interp handles this + + hb_interp #(.IWIDTH(18),.OWIDTH(18),.ACCWIDTH(24)) hb_interp_i + (.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)); + hb_interp #(.IWIDTH(18),.OWIDTH(18),.ACCWIDTH(24)) hb_interp_q + (.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)); + + small_hb_int #(.WIDTH(18)) small_hb_interp_i + (.clk(clk),.rst(rst),.bypass(~enable_hb2),.stb_in(strobe_hb2),.data_in(hb1_i), + .output_rate(interp_rate),.stb_out(strobe_cic),.data_out(hb2_i)); + small_hb_int #(.WIDTH(18)) small_hb_interp_q + (.clk(clk),.rst(rst),.bypass(~enable_hb2),.stb_in(strobe_hb2),.data_in(hb1_q), + .output_rate(interp_rate),.stb_out(strobe_cic),.data_out(hb2_q)); + + cic_interp #(.bw(18),.N(4),.log2_of_max_rate(7)) + cic_interp_i(.clock(clk),.reset(rst),.enable(run),.rate(interp_rate), + .strobe_in(strobe_cic),.strobe_out(1), + .signal_in(hb2_i),.signal_out(i_interp)); + + cic_interp #(.bw(18),.N(4),.log2_of_max_rate(7)) + cic_interp_q(.clock(clk),.reset(rst),.enable(run),.rate(interp_rate), + .strobe_in(strobe_cic),.strobe_out(1), + .signal_in(hb2_q),.signal_out(q_interp)); + + assign strobe = strobe_hb1; + + localparam cwidth = 24; // was 18 + localparam zwidth = 24; // was 16 + + wire [cwidth-1:0] da_c, db_c; + + cordic_z24 #(.bitwidth(cwidth)) + cordic(.clock(clk), .reset(rst), .enable(run), + .xi({i_interp,{(cwidth-18){1'b0}}}),.yi({q_interp,{(cwidth-18){1'b0}}}), + .zi(phase[31:32-zwidth]), + .xo(da_c),.yo(db_c),.zo() ); + + MULT18X18S MULT18X18S_inst + (.P(prod_i), // 36-bit multiplier output + .A(da_c[cwidth-1:cwidth-18]), // 18-bit multiplier input + .B({{2{scale_i[15]}},scale_i}), // 18-bit multiplier input + .C(clk), // Clock input + .CE(1), // Clock enable input + .R(rst) // Synchronous reset input + ); + + MULT18X18S MULT18X18S_inst_2 + (.P(prod_q), // 36-bit multiplier output + .A(db_c[cwidth-1:cwidth-18]), // 18-bit multiplier input + .B({{2{scale_q[15]}},scale_q}), // 18-bit multiplier input + .C(clk), // Clock input + .CE(1), // Clock enable input + .R(rst) // Synchronous reset input + ); + + always @(posedge clk) + case(dacmux_a) + 0 : dac_a <= prod_i[28:13]; + 1 : dac_a <= prod_q[28:13]; + default : dac_a <= 0; + endcase // case(dacmux_a) + + always @(posedge clk) + case(dacmux_b) + 0 : dac_b <= prod_i[28:13]; + 1 : dac_b <= prod_q[28:13]; + default : dac_b <= 0; + endcase // case(dacmux_b) + + assign debug = {strobe_cic, strobe_hb1, strobe_hb2,run}; + +endmodule // dsp_core |