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-rw-r--r--fpga/usrp2/sdr_lib/rssi.v30
1 files changed, 30 insertions, 0 deletions
diff --git a/fpga/usrp2/sdr_lib/rssi.v b/fpga/usrp2/sdr_lib/rssi.v
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index 000000000..e45e2148c
--- /dev/null
+++ b/fpga/usrp2/sdr_lib/rssi.v
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+
+
+module rssi (input clock, input reset, input enable,
+ input [11:0] adc, output [15:0] rssi, output [15:0] over_count);
+
+ wire over_hi = (adc == 12'h7FF);
+ wire over_lo = (adc == 12'h800);
+ wire over = over_hi | over_lo;
+
+ reg [25:0] over_count_int;
+ always @(posedge clock)
+ if(reset | ~enable)
+ over_count_int <= #1 26'd0;
+ else
+ over_count_int <= #1 over_count_int + (over ? 26'd65535 : 26'd0) - over_count_int[25:10];
+
+ assign over_count = over_count_int[25:10];
+
+ wire [11:0] abs_adc = adc[11] ? ~adc : adc;
+
+ reg [25:0] rssi_int;
+ always @(posedge clock)
+ if(reset | ~enable)
+ rssi_int <= #1 26'd0;
+ else
+ rssi_int <= #1 rssi_int + abs_adc - rssi_int[25:10];
+
+ assign rssi = rssi_int[25:10];
+
+endmodule // rssi