diff --git a/boards/TinyFPGA_BX/bootloader.v b/boards/TinyFPGA_BX/bootloader.v
index 89e3f2b..bf7a601 100644
--- a/boards/TinyFPGA_BX/bootloader.v
+++ b/boards/TinyFPGA_BX/bootloader.v
@@ -79,6 +79,8 @@ module bootloader (
   wire usb_n_tx;
   wire usb_p_rx;
   wire usb_n_rx;
+  wire usb_p_rx_io;
+  wire usb_n_rx_io;
   wire usb_tx_en;
 
   tinyfpga_bootloader tinyfpga_bootloader_inst (
@@ -98,10 +100,44 @@ module bootloader (
   );
 
   assign pin_pu = 1'b1;
-  assign pin_usbp = usb_tx_en ? usb_p_tx : 1'bz;
-  assign pin_usbn = usb_tx_en ? usb_n_tx : 1'bz;
-  assign usb_p_rx = usb_tx_en ? 1'b1 : pin_usbp;
-  assign usb_n_rx = usb_tx_en ? 1'b0 : pin_usbn;
+  assign usb_p_rx = usb_tx_en ? 1'b1 : usb_p_rx_io;
+  assign usb_n_rx = usb_tx_en ? 1'b0 : usb_n_rx_io;
+
+  SB_IO #(
+     .PIN_TYPE(6'b101001),
+     .PULLUP(1'b0),
+     .NEG_TRIGGER(1'b0),
+     .IO_STANDARD("SB_LVCMOS")
+   ) io_dp_I (
+     .PACKAGE_PIN(pin_usbp),
+     .LATCH_INPUT_VALUE(1'b0),
+     .CLOCK_ENABLE(1'b1),
+     .INPUT_CLK(1'b0),
+     .OUTPUT_CLK(1'b0),
+     .OUTPUT_ENABLE(usb_tx_en),
+     .D_OUT_0(usb_p_tx),
+     .D_OUT_1(1'b0),
+     .D_IN_0(usb_p_rx_io),
+     .D_IN_1()
+  );
+
+  SB_IO #(
+     .PIN_TYPE(6'b101001),
+     .PULLUP(1'b0),
+     .NEG_TRIGGER(1'b0),
+     .IO_STANDARD("SB_LVCMOS")
+   ) io_dn_I (
+     .PACKAGE_PIN(pin_usbn),
+     .LATCH_INPUT_VALUE(1'b0),
+     .CLOCK_ENABLE(1'b1),
+     .INPUT_CLK(1'b0),
+     .OUTPUT_CLK(1'b0),
+     .OUTPUT_ENABLE(usb_tx_en),
+     .D_OUT_0(usb_n_tx),
+     .D_OUT_1(1'b0),
+     .D_IN_0(usb_n_rx_io),
+     .D_IN_1()
+  );
 
   assign reset = 1'b0; 
 endmodule
diff --git a/common/serial.v b/common/serial.v
index 360d204..b776c70 100644
--- a/common/serial.v
+++ b/common/serial.v
@@ -11,7 +11,7 @@ module width_adapter #(
 
   output data_out_put,
   input data_out_free,
-  output [OUTPUT_WIDTH-1:0] data_out,
+  output [OUTPUT_WIDTH-1:0] data_out
 );
 
   generate
diff --git a/common/usb_fs_in_arb.v b/common/usb_fs_in_arb.v
index a331406..186a272 100644
--- a/common/usb_fs_in_arb.v
+++ b/common/usb_fs_in_arb.v
@@ -20,6 +20,8 @@ module usb_fs_in_arb #(
   always @* begin
     grant = 0;
 
+    arb_in_ep_data <= 0;
+
     for (i = 0; i < NUM_IN_EPS; i = i + 1) begin
       in_ep_grant[i] <= 0;
 
@@ -29,9 +31,5 @@ module usb_fs_in_arb #(
         grant = 1;
       end
     end
-
-    if (!grant) begin
-      arb_in_ep_data <= 0;
-    end
   end
 endmodule
diff --git a/common/usb_fs_in_pe.v b/common/usb_fs_in_pe.v
index d999de4..16b9faf 100644
--- a/common/usb_fs_in_pe.v
+++ b/common/usb_fs_in_pe.v
@@ -51,7 +51,7 @@ module usb_fs_in_pe #(
   // Data payload to send if any
   output tx_data_avail,
   input tx_data_get,
-  output reg [7:0] tx_data = 0
+  output reg [7:0] tx_data
 );
 
   ////////////////////////////////////////////////////////////////////////////////
@@ -166,6 +166,8 @@ module usb_fs_in_pe #(
       always @* begin
         in_ep_acked[ep_num] <= 0;
 
+        ep_state_next[ep_num] <= ep_state[ep_num];
+
         if (in_ep_stall[ep_num]) begin
           ep_state_next[ep_num] <= STALL;
 
@@ -277,9 +279,11 @@ module usb_fs_in_pe #(
   reg rollback_in_xfr;
 
   always @* begin
+    in_xfr_state_next <= in_xfr_state;
     in_xfr_start <= 0;
     in_xfr_end <= 0;
     tx_pkt_start <= 0;
+    tx_pid <= 4'b0000;
     rollback_in_xfr <= 0;
 
     case (in_xfr_state)
@@ -344,6 +348,9 @@ module usb_fs_in_pe #(
     endcase
   end
 
+  always @(posedge clk)
+      tx_data <= in_data_buffer[buffer_get_addr];
+
   integer j;
   always @(posedge clk) begin
     if (reset) begin
@@ -352,8 +359,6 @@ module usb_fs_in_pe #(
     end else begin
       in_xfr_state <= in_xfr_state_next;
 
-      tx_data <= in_data_buffer[buffer_get_addr];
-
       if (setup_token_received) begin
         data_toggle[rx_endp] <= 1;
       end
diff --git a/common/usb_fs_out_pe.v b/common/usb_fs_out_pe.v
index 2e43be5..26d0802 100644
--- a/common/usb_fs_out_pe.v
+++ b/common/usb_fs_out_pe.v
@@ -14,7 +14,7 @@ module usb_fs_out_pe #(
   output [NUM_OUT_EPS-1:0] out_ep_data_avail,
   output reg [NUM_OUT_EPS-1:0] out_ep_setup = 0,
   input [NUM_OUT_EPS-1:0] out_ep_data_get,
-  output reg [7:0] out_ep_data = 0,
+  output reg [7:0] out_ep_data,
   input [NUM_OUT_EPS-1:0] out_ep_stall,
   output reg [NUM_OUT_EPS-1:0] out_ep_acked = 0,
 
@@ -154,6 +154,8 @@ module usb_fs_out_pe #(
     for (ep_num = 0; ep_num < NUM_OUT_EPS; ep_num = ep_num + 1) begin
       always @* begin
 
+        ep_state_next[ep_num] <= ep_state[ep_num];
+
         if (out_ep_stall[ep_num]) begin
           ep_state_next[ep_num] <= STALL;
 
@@ -272,7 +274,9 @@ module usb_fs_out_pe #(
   ////////////////////////////////////////////////////////////////////////////////
 
   always @* begin
+    out_ep_acked <= 0;
     out_xfr_start <= 0;
+    out_xfr_state_next <= out_xfr_state;
     tx_pkt_start <= 0;
     tx_pid <= 0;
     new_pkt_end <= 0;