diff --git a/docs/ultraplus.html b/docs/ultraplus.html
index e5706e6..da109b5 100644
--- a/docs/ultraplus.html
+++ b/docs/ultraplus.html
@@ -248,5 +248,20 @@ can be used as an open-drain IO using the standard IO cell.</p>
 <tr><td>RGB2_CURRENT[5:0]</td><td>(0, 30, CBIT_[7:2])</td></tr>
 <tr><td>CURRENT_MODE</td><td>(0, 28, CBIT_4)</td></tr>
 
+</table>
+
+<h2>IO Changes</h2>
+<p>The IO tiles contain a few new bits compared to earlier ice40 devices.
+	The bits <span style="font-family:monospace">padeb_test_0</span> and
+	<span style="font-family:monospace">padeb_test_1</span> are set for all pins,
+	even unused ones, unless set as an output.</p>
+<p>There are also some new bits used to control the pullup strength:</p>
+<table class="ctab">
+<tr><th>Strength</th><th>Cell 0</th><th>Cell 1</th></tr>
+<tr><td>3.3k&Omega;</td><td>cf_bit_32<br/>B7[10]</td><td>cf_bit_36<br/>B13[10]</td></tr>
+<tr><td>6.8k&Omega;</td><td>cf_bit_33<br/>B6[10]</td><td>cf_bit_37<br/>B12[10]</td></tr>
+<tr><td>10k&Omega;</td><td>cf_bit_34<br/>B7[15]</td><td>cf_bit_38<br/>B13[15]</td></tr>
+<tr><td>100k&Omega;<br/>(default)</td><td>!cf_bit_35<br/>!B6[15]</td><td>!cf_bit_39<br/>!B12[15]</td></tr>
+
 </table>
 </body></html>
diff --git a/icebox/icebox.py b/icebox/icebox.py
index ce2a3cd..6b0dfd8 100644
--- a/icebox/icebox.py
+++ b/icebox/icebox.py
@@ -4808,13 +4808,25 @@ logictile_384_db.append([["B1[50]"], "CarryInSet"])
 iotile_t_5k_db = list(iotile_t_db)
 iotile_t_5k_db.append([["B14[15]"], "IoCtrl", "padeb_test_1"])
 iotile_t_5k_db.append([["B15[14]"], "IoCtrl", "padeb_test_0"])
+iotile_t_5k_db.append([["B7[10]"], "IoCtrl", "cf_bit_32"])
+iotile_t_5k_db.append([["B6[10]"], "IoCtrl", "cf_bit_33"])
+iotile_t_5k_db.append([["B7[15]"], "IoCtrl", "cf_bit_34"])
 iotile_t_5k_db.append([["B6[15]"], "IoCtrl", "cf_bit_35"])
+iotile_t_5k_db.append([["B13[10]"], "IoCtrl", "cf_bit_36"])
+iotile_t_5k_db.append([["B12[10]"], "IoCtrl", "cf_bit_37"])
+iotile_t_5k_db.append([["B13[15]"], "IoCtrl", "cf_bit_38"])
 iotile_t_5k_db.append([["B12[15]"], "IoCtrl", "cf_bit_39"])
 
 iotile_b_5k_db = list(iotile_b_db)
 iotile_b_5k_db.append([["B14[15]"], "IoCtrl", "padeb_test_1"])
 iotile_b_5k_db.append([["B15[14]"], "IoCtrl", "padeb_test_0"])
+iotile_b_5k_db.append([["B7[10]"], "IoCtrl", "cf_bit_32"])
+iotile_b_5k_db.append([["B6[10]"], "IoCtrl", "cf_bit_33"])
+iotile_b_5k_db.append([["B7[15]"], "IoCtrl", "cf_bit_34"])
 iotile_b_5k_db.append([["B6[15]"], "IoCtrl", "cf_bit_35"])
+iotile_b_5k_db.append([["B13[10]"], "IoCtrl", "cf_bit_36"])
+iotile_b_5k_db.append([["B12[10]"], "IoCtrl", "cf_bit_37"])
+iotile_b_5k_db.append([["B13[15]"], "IoCtrl", "cf_bit_38"])
 iotile_b_5k_db.append([["B12[15]"], "IoCtrl", "cf_bit_39"])
 
 for db in [iotile_l_db, iotile_r_db, iotile_t_db, iotile_b_db, iotile_t_5k_db, iotile_b_5k_db, logictile_db, logictile_5k_db, logictile_8k_db, logictile_384_db, rambtile_db, ramttile_db, rambtile_5k_db, ramttile_5k_db, rambtile_8k_db, ramttile_8k_db, dsp0_5k_db, dsp1_5k_db, dsp2_5k_db, dsp3_5k_db, ipcon_5k_db]: