diff --git a/grc/demapping/gsm_sdcch8_demapper.xml b/grc/demapping/gsm_sdcch8_demapper.xml
index 38a8112..ab11d64 100644
--- a/grc/demapping/gsm_sdcch8_demapper.xml
+++ b/grc/demapping/gsm_sdcch8_demapper.xml
@@ -3,7 +3,7 @@
   <name>SDCCH/8 demapper</name>
   <key>gsm_sdcch8_demapper</key>
   <import>import grgsm</import>
-  <make>grgsm.universal_ctrl_chans_demapper($timeslot_nr, $starts_fn_mod51, $channel_types)</make>
+  <make>grgsm.universal_ctrl_chans_demapper($timeslot_nr, $downlink_starts_fn_mod51, $downlink_channel_types, $uplink_starts_fn_mod51, $uplink_channel_types)</make>
 
   <param>
     <name>Timeslot</name>
@@ -14,7 +14,7 @@
   </param>
 
   <param>
-    <name>starts_fn_mod51</name>
+    <name>downlink_starts_fn_mod51</name>
     <key>starts_fn_mod51</key>
     <value>[0,4,8,12,16,20,24,28,32,36,40,44]</value>
     <type>int_vector</type>
@@ -22,7 +22,23 @@
   </param>
 
   <param>
-    <name>channel_types</name>
+    <name>downlink_channel_types</name>
+    <key>channel_types</key>
+    <value>[8,8,8,8,8,8,8,8,136,136,136,136]</value>
+    <type>int_vector</type>
+    <hide>all</hide>
+  </param>
+
+  <param>
+    <name>uplink_starts_fn_mod51</name>
+    <key>starts_fn_mod51</key>
+    <value>[0,4,8,12,16,20,24,28,32,36,40,44]</value>
+    <type>int_vector</type>
+    <hide>all</hide>
+  </param>
+
+  <param>
+    <name>uplink_channel_types</name>
     <key>channel_types</key>
     <value>[8,8,8,8,8,8,8,8,136,136,136,136]</value>
     <type>int_vector</type>
@@ -42,4 +58,4 @@
       Demapper for SDCCH/8 + SACCH/C8 control channels.
       This corresponds to channel combination vii specified in GSM 05.02, section 6.4
   </doc>
-</block>
\ No newline at end of file
+</block>