--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/duart28c/src/vsrc/boot_ctrl.v	Wed Jul 29 07:59:20 2020 +0000
@@ -0,0 +1,35 @@
+/*
+ * This module encapsulates the boot control addition for DUART28C.
+ */
+
+module boot_ctrl (GND, P_3V3, ChanB_RTS, ChanB_DTR);
+
+input GND, P_3V3;
+input ChanB_RTS, ChanB_DTR;
+
+wire CTL1_out, CTL2_out;
+
+/* pull-up resistors on FT2232D outputs */
+
+resistor ChanB_RTS_pullup (ChanB_RTS, P_3V3);
+resistor ChanB_DTR_pullup (ChanB_DTR, P_3V3);
+
+/* open drain buffers */
+
+od_buffer_ic_common od_buf_common (.Vcc(P_3V3),
+				   .GND(GND)
+	);
+
+capacitor od_buf_bypass_cap (P_3V3, GND);
+
+od_buffer_ic_slot buf_CTL1 (.A(ChanB_RTS), .Y(CTL1_out));
+od_buffer_ic_slot buf_CTL2 (.A(ChanB_DTR), .Y(CTL2_out));
+
+/* header connector */
+
+header_3pin ctl_if (.pin_1(GND),
+		    .pin_2(CTL1_out),
+		    .pin_3(CTL2_out)
+	);
+
+endmodule