diff options
Diffstat (limited to 'fpga/usrp2/sdr_lib/hb/halfband_interp.v')
| -rw-r--r-- | fpga/usrp2/sdr_lib/hb/halfband_interp.v | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/fpga/usrp2/sdr_lib/hb/halfband_interp.v b/fpga/usrp2/sdr_lib/hb/halfband_interp.v new file mode 100644 index 000000000..83bdc9fad --- /dev/null +++ b/fpga/usrp2/sdr_lib/hb/halfband_interp.v @@ -0,0 +1,138 @@ +// +// Copyright 2011 Ettus Research LLC +// +// 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/>. +// + + + +module halfband_interp + (input clock, input reset, input enable, + input strobe_in, input strobe_out, + input [15:0] signal_in_i, input [15:0] signal_in_q, + output reg [15:0] signal_out_i, output reg [15:0] signal_out_q, + output wire [12:0] debug); + + wire [15:0] coeff_ram_out; + wire [15:0] data_ram_out_i; + wire [15:0] data_ram_out_q; + + wire [3:0] data_rd_addr; + reg [3:0] data_wr_addr; + reg [2:0] coeff_rd_addr; + + wire filt_done; + + wire [15:0] mac_out_i; + wire [15:0] mac_out_q; + reg [15:0] delayed_middle_i, delayed_middle_q; + wire [7:0] shift = 8'd9; + + reg stb_out_happened; + + wire [15:0] data_ram_out_i_b; + + always @(posedge clock) + if(strobe_in) + stb_out_happened <= #1 1'b0; + else if(strobe_out) + stb_out_happened <= #1 1'b1; + +assign debug = {filt_done,data_rd_addr,data_wr_addr,coeff_rd_addr}; + + wire [15:0] signal_out_i = stb_out_happened ? mac_out_i : delayed_middle_i; + wire [15:0] signal_out_q = stb_out_happened ? mac_out_q : delayed_middle_q; + +/* always @(posedge clock) + if(reset) + begin + signal_out_i <= #1 16'd0; + signal_out_q <= #1 16'd0; + end + else if(strobe_in) + begin + signal_out_i <= #1 delayed_middle_i; // Multiply by 1 for middle coeff + signal_out_q <= #1 delayed_middle_q; + end + //else if(filt_done&stb_out_happened) + else if(stb_out_happened) + begin + signal_out_i <= #1 mac_out_i; + signal_out_q <= #1 mac_out_q; + end +*/ + + always @(posedge clock) + if(reset) + coeff_rd_addr <= #1 3'd0; + else if(coeff_rd_addr != 3'd0) + coeff_rd_addr <= #1 coeff_rd_addr + 3'd1; + else if(strobe_in) + coeff_rd_addr <= #1 3'd1; + + reg filt_done_d1; + always@(posedge clock) + filt_done_d1 <= #1 filt_done; + + always @(posedge clock) + if(reset) + data_wr_addr <= #1 4'd0; + //else if(strobe_in) + else if(filt_done & ~filt_done_d1) + data_wr_addr <= #1 data_wr_addr + 4'd1; + + always @(posedge clock) + if(coeff_rd_addr == 3'd7) + begin + delayed_middle_i <= #1 data_ram_out_i_b; + // delayed_middle_q <= #1 data_ram_out_q_b; + end + +// always @(posedge clock) +// if(reset) +// data_rd_addr <= #1 4'd0; +// else if(strobe_in) +// data_rd_addr <= #1 data_wr_addr + 4'd1; +// else if(!filt_done) +// data_rd_addr <= #1 data_rd_addr + 4'd1; +// else +// data_rd_addr <= #1 data_wr_addr; + + wire [3:0] data_rd_addr1 = data_wr_addr + {1'b0,coeff_rd_addr}; + wire [3:0] data_rd_addr2 = data_wr_addr + 15 - {1'b0,coeff_rd_addr}; +// always @(posedge clock) +// if(reset) +// filt_done <= #1 1'b1; +// else if(strobe_in) + // filt_done <= #1 1'b0; +// else if(coeff_rd_addr == 4'd0) +// filt_done <= #1 1'b1; + + assign filt_done = (coeff_rd_addr == 3'd0); + + coeff_ram coeff_ram ( .clock(clock),.rd_addr({1'b0,coeff_rd_addr}),.rd_data(coeff_ram_out) ); + + ram16_2sum data_ram_i ( .clock(clock),.write(strobe_in),.wr_addr(data_wr_addr),.wr_data(signal_in_i), + .rd_addr1(data_rd_addr1),.rd_addr2(data_rd_addr2),.rd_data(data_ram_out_i_b),.sum(data_ram_out_i)); + + ram16_2sum data_ram_q ( .clock(clock),.write(strobe_in),.wr_addr(data_wr_addr),.wr_data(signal_in_q), + .rd_addr1(data_rd_addr1),.rd_addr2(data_rd_addr2),.rd_data(data_ram_out_q)); + + mac mac_i (.clock(clock),.reset(reset),.enable(~filt_done),.clear(strobe_in), + .x(data_ram_out_i),.y(coeff_ram_out),.shift(shift),.z(mac_out_i) ); + + mac mac_q (.clock(clock),.reset(reset),.enable(~filt_done),.clear(strobe_in), + .x(data_ram_out_q),.y(coeff_ram_out),.shift(shift),.z(mac_out_q) ); + +endmodule // halfband_interp |