Merged r9433:9527 from features/gr-usrp2 into trunk. Adds usrp2 and gr-usrp2 top-level components. Trunk passes distcheck with mb-gcc installed, but currently not without them. The key issue is that when mb-gcc is not installed, the build system skips over the usrp2/firmware directory, and the firmware include files don't get put into the dist tarball. But we can't do the usual DIST_SUBDIRS method as the firmware is a subpackage.

git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@9528 221aa14e-8319-0410-a670-987f0aec2ac5

1 files changed, 30 insertions, 0 deletions

diff --git a/usrp2/fpga/sdr_lib/rssi.v b/usrp2/fpga/sdr_lib/rssi.v
new file mode 100644
index 000000000..e45e2148c
--- /dev/null
+++ b/usrp2/fpga/sdr_lib/rssi.v
@@ -0,0 +1,30 @@
+
+
+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