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authorjcorgan <jcorgan@221aa14e-8319-0410-a670-987f0aec2ac5>2008-09-08 01:00:12 +0000
committerjcorgan <jcorgan@221aa14e-8319-0410-a670-987f0aec2ac5>2008-09-08 01:00:12 +0000
commit61f2f0214c5999ea42a368a4fc99f03d8eb28d1e (patch)
treee7e24a9adc05ff1422fe3ada9926a51634741b47 /control_lib/wb_semaphore.v
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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
Diffstat (limited to 'control_lib/wb_semaphore.v')
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1 files changed, 42 insertions, 0 deletions
diff --git a/control_lib/wb_semaphore.v b/control_lib/wb_semaphore.v
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+++ b/control_lib/wb_semaphore.v
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+
+// up to 8 semaphores
+
+// After a read operation, the semaphore is always locked
+// If it was already locked before the read (meaning someone else holds the lock)
+// then a 1 is returned
+// If it was not already locked (meaning the reader now holds the lock)
+// then a 0 is returned
+
+// A write operation clears the lock
+
+module wb_semaphore
+ #(parameter count=8, DBUS_WIDTH=32)
+ (input wb_clk_i,
+ input wb_rst_i,
+ input [DBUS_WIDTH-1:0] wb_dat_i,
+ input [2:0] wb_adr_i,
+ input wb_cyc_i,
+ input wb_stb_i,
+ input wb_we_i,
+ output wb_ack_o,
+ output [DBUS_WIDTH-1:0] wb_dat_o);
+
+ reg [count-1:0] locked;
+
+ always @(posedge clock)
+ if(wb_rst_i)
+ locked <= {count{1'b0}};
+ else if(wb_stb_i)
+ if(wb_we_i)
+ locked[adr_i] <= 1'b0;
+ else
+ locked[adr_i] <= 1'b1;
+
+ assign wb_dat_o[DBUS_WIDTH-1:1] = {(DBUS_WIDTH-1){1'b0}};
+ assign wb_dat_o[0] = locked[adr_i];
+ assign wb_ack_o = wb_stb_i;
+
+
+endmodule // wb_semaphore
+
+