diff --git a/tools/bittool.cc b/tools/bittool.cc
index b38af32d..26b01522 100644
--- a/tools/bittool.cc
+++ b/tools/bittool.cc
@@ -40,9 +40,67 @@ int ListConfigPackets(int argc, char *argv[]) {
 	return 0;
 }
 
+int DumpDebugbitstreamFrameAddresses(int argc, char *argv[]) {
+	if (argc < 1) {
+		std::cerr << "ERROR: no input specified" << std::endl;
+		std::cerr << "Usage: " << argv[0]
+			  << "dump_debugbitstream_frame_addresses <bit_file>"
+			  << std::endl;
+		return 1;
+	}
+
+	auto in_file_name = argv[0];
+	auto in_file = prjxray::MemoryMappedFile::InitWithFile(in_file_name);
+	if (!in_file) {
+		std::cerr << "Unable to open bit file: " << in_file_name
+			  << std::endl;
+		return 1;
+	}
+
+	auto in_bytes = absl::Span<uint8_t>(
+			static_cast<uint8_t*>(in_file->data()),
+			in_file->size());
+	auto reader = xc7series::BitstreamReader::InitWithBytes(in_bytes);
+	if (!reader) {
+		std::cerr << "Input doesn't look like a bitstream"
+			  << std::endl;
+		return 1;
+	}
+
+	bool found_one_lout = false;
+	for (auto packet : *reader) {
+		if ((packet.opcode() !=
+		     xc7series::ConfigurationPacket::Opcode::Write) ||
+		    (packet.address() !=
+		     xc7series::ConfigurationRegister::LOUT)) {
+			continue;
+		}
+
+		if (packet.data().size() != 1) {
+			std::cerr << "Write to FAR with word_count != 1"
+				  << std::endl;
+			continue;
+		}
+
+		found_one_lout = true;
+		std::cout << std::dec << packet.data()[0] << std::endl;
+	}
+
+	if (!found_one_lout) {
+		std::cerr << "No LOUT writes found.  Was "
+			  << "BITSTREAM.GENERAL.DEBUGBITSTREAM set to YES?"
+			  << std::endl;
+		return 1;
+	}
+
+	return 0;
+}
+
 int main(int argc, char *argv[]) {
 	Action actions[] = {
 		{ "list_config_packets", ListConfigPackets },
+		{ "dump_debugbitstream_frame_addresses",
+			DumpDebugbitstreamFrameAddresses },
 	};
 
 	gflags::SetUsageMessage(