L/R and U/D conns should not be copied to CIB_PIC_{B0, B_DUMMY} tiles.
diff --git a/fuzzers/machxo2/035-copy-cib_ebr0/fuzzer.py b/fuzzers/machxo2/035-copy-cib_ebr0/fuzzer.py
index af09603..a5a6841 100644
--- a/fuzzers/machxo2/035-copy-cib_ebr0/fuzzer.py
+++ b/fuzzers/machxo2/035-copy-cib_ebr0/fuzzer.py
@@ -1,5 +1,6 @@
 import dbcopy
 import pytrellis
+import nets
 
 # Based on prior fuzzing conjecture that CIB_EBR
 # 0,1,2, and DUMMY, and CIB_PIC_B0 and CIB_PIC_B_DUMMY have the same layout.
@@ -8,7 +9,16 @@
 # need to be manually tweaked to convert U_/D_ prefixes to G_ prefixes. There's
 # too much shared routing to justify rerunning the fuzzers.
 
-shared_tiles = ["CIB_EBR1", "CIB_EBR2", "CIB_EBR_DUMMY", "CIB_PIC_B0", "CIB_PIC_B_DUMMY"]
+shared_tiles = ["CIB_EBR1", "CIB_EBR2", "CIB_EBR_DUMMY"]
+shared_tiles_no_lrudconns = ["CIB_PIC_B0", "CIB_PIC_B_DUMMY"]
+
+# Only globals are the BRANCH connections which are fed by U_/D_ conns with
+# G_ prefixes (muxed).
+def exclude_lrud_conns(conn):
+    src = conn.source
+    sink = conn.sink
+
+    return not (src.startswith("G_CLKO") or sink.startswith("G_CLKI"))
 
 def main():
     pytrellis.load_database("../../../database")
@@ -16,5 +26,9 @@
     for dest in shared_tiles:
         dbcopy.dbcopy("MachXO2", "LCMXO2-1200HC", "CIB_EBR0", dest)
 
+    for dest in shared_tiles_no_lrudconns:
+        dbcopy.dbcopy("MachXO2", "LCMXO2-1200HC", "CIB_EBR0", dest, copy_conns=False)
+        dbcopy.copy_conns_with_predicate("MachXO2", "LCMXO2-1200HC", "CIB_EBR0", dest, exclude_lrud_conns)
+
 if __name__ == "__main__":
     main()