diff --git a/lib_xua/api/xua_audiohub.h b/lib_xua/api/xua_audiohub.h
index ed9da2aa..c056d591 100644
--- a/lib_xua/api/xua_audiohub.h
+++ b/lib_xua/api/xua_audiohub.h
@@ -38,12 +38,16 @@
  *
  *  \param i_SoftPll        Interface to software PLL task
  *
- *  \param c_spdif_tx       Channel connected to S/PDIF transmiter core from lib_spdif
+ *  \param c_spdif_tx       Channel connected to S/PDIF transmitter core from lib_spdif
  *
  *  \param c_dig            Channel connected to the clockGen() thread for
  *                          receiving/transmitting samples
  * 
- *  \param c_mclk_change    Channel notifying clockgen of an mclk frequency change
+ *  \param c_mclk_change    Channel notifying ep_buffer of an mclk frequency change and sync for stable clock
+ * 
+ *  \param dfuInterface     Interface supporting DFU methods
+ * 
+ *  \param c_pdm_in         Channel for receiving decimated PDM samples
  */
 void XUA_AudioHub(chanend ?c_aud,
     clock ?clk_audio_mclk,
@@ -61,12 +65,14 @@ void XUA_AudioHub(chanend ?c_aud,
 #endif
 #if (XUA_SPDIF_RX_EN || XUA_ADAT_RX_EN || defined(__DOXYGEN__))
     , chanend c_dig
+#endif
+#if (XUA_SYNCMODE == XUA_SYNCMODE_SYNC || XUA_SPDIF_RX_EN || XUA_ADAT_RX_EN || defined(__DOXYGEN__))
     , chanend c_mclk_change
 #endif
-#if (XUD_TILE != 0) && (AUDIO_IO_TILE == 0) && (XUA_DFU_EN == 1)
+#if (((XUD_TILE != 0) && (AUDIO_IO_TILE == 0) && (XUA_DFU_EN == 1)) || defined(__DOXYGEN__))
    , server interface i_dfu ?dfuInterface
 #endif
-#if (XUA_NUM_PDM_MICS > 0)
+#if (XUA_NUM_PDM_MICS > 0 || defined(__DOXYGEN__))
     , chanend c_pdm_in
 #endif
 );
diff --git a/lib_xua/api/xua_buffer.h b/lib_xua/api/xua_buffer.h
index 0e2dd3ee..10539bfa 100644
--- a/lib_xua/api/xua_buffer.h
+++ b/lib_xua/api/xua_buffer.h
@@ -53,6 +53,7 @@ void XUA_Buffer(
 #endif
             , chanend c_aud
 #if (XUA_SYNCMODE == XUA_SYNCMODE_SYNC) || defined(__DOYXGEN__)
+            , chanend c_mclk_change
     #if (!XUA_USE_SW_PLL) || defined(__DOXYGEN__)
             , client interface pll_ref_if i_pll_ref
     #endif
@@ -88,6 +89,7 @@ void XUA_Buffer_Ep(chanend c_aud_out,
             , chanend c_buff_ctrl
 #endif
 #if (XUA_SYNCMODE == XUA_SYNCMODE_SYNC) || defined(__DOYXGEN__)
+            , chanend c_mclk_change
     #if (!XUA_USE_SW_PLL) || defined(__DOXYGEN__)
             , client interface pll_ref_if i_pll_ref
     #endif
diff --git a/lib_xua/src/core/audiohub/xua_audiohub.xc b/lib_xua/src/core/audiohub/xua_audiohub.xc
index ca499f28..b4a62e9e 100755
--- a/lib_xua/src/core/audiohub/xua_audiohub.xc
+++ b/lib_xua/src/core/audiohub/xua_audiohub.xc
@@ -641,6 +641,8 @@ void XUA_AudioHub(chanend ?c_aud, clock ?clk_audio_mclk, clock ?clk_audio_bclk,
 #endif
 #if (XUA_ADAT_RX_EN || XUA_SPDIF_RX_EN)
     , chanend c_dig_rx
+#endif
+#if (XUA_SYNCMODE == XUA_SYNCMODE_SYNC || XUA_SPDIF_RX_EN || XUA_ADAT_RX_EN)
     , chanend c_mclk_change
 #endif
 #if (XUD_TILE != 0) && (AUDIO_IO_TILE == 0) && (XUA_DFU_EN == 1)
@@ -807,12 +809,12 @@ void XUA_AudioHub(chanend ?c_aud, clock ?clk_audio_mclk, clock ?clk_audio_bclk,
 
             /* User code should configure audio harware for SampleFreq/MClk etc */
             AudioHwConfig(curFreq, mClk, dsdMode, curSamRes_DAC, curSamRes_ADC);
-#if (XUA_SPDIF_RX_EN || XUA_ADAT_RX_EN)
+#if (XUA_SYNCMODE == XUA_SYNCMODE_SYNC || XUA_SPDIF_RX_EN || XUA_ADAT_RX_EN)
             /* Notify clockgen of new mCLk */
             c_mclk_change <: mClk;
             c_mclk_change <: curFreq;
 
-            /* Wait for ACK back from clockgen to signal clocks all good */
+            /* Wait for ACK back from clockgen or ep_buffer to signal clocks all good */
             c_mclk_change :> int _;
 #endif
 
diff --git a/lib_xua/src/core/buffer/ep/ep_buffer.xc b/lib_xua/src/core/buffer/ep/ep_buffer.xc
index 608f301b..c5261512 100644
--- a/lib_xua/src/core/buffer/ep/ep_buffer.xc
+++ b/lib_xua/src/core/buffer/ep/ep_buffer.xc
@@ -105,6 +105,7 @@ void XUA_Buffer(
 #endif
     , chanend c_aud
 #if (XUA_SYNCMODE == XUA_SYNCMODE_SYNC)
+    , chanend c_mclk_change
     #if(XUA_USE_SW_PLL)
     , chanend c_sw_pll
     #else
@@ -145,6 +146,7 @@ void XUA_Buffer(
                 , c_buff_ctrl
 #endif
 #if (XUA_SYNCMODE == XUA_SYNCMODE_SYNC)
+                , c_mclk_change
     #if(XUA_USE_SW_PLL)
                , c_sw_pll
     #else
@@ -199,6 +201,7 @@ void XUA_Buffer_Ep(register chanend c_aud_out,
     , chanend c_buff_ctrl
 #endif
 #if (XUA_SYNCMODE == XUA_SYNCMODE_SYNC)
+    , chanend c_mclk_change
     #if (XUA_USE_SW_PLL)
     , chanend c_sw_pll
     #else
@@ -1030,14 +1033,22 @@ void XUA_Buffer_Ep(register chanend c_aud_out,
                 break;
 #endif  /* ifdef MIDI */
 
-#if ((XUA_SYNCMODE == XUA_SYNCMODE_SYNC) && XUA_USE_SW_PLL)
+#if (XUA_SYNCMODE == XUA_SYNCMODE_SYNC)
+            case c_mclk_change :> u_tmp:
+                unsigned selected_mclk_rate = u_tmp;
+                c_mclk_change :> u_tmp; /* Sample rate we discard */
+                c_mclk_change <: 0;     /* ACK back to audio to release */
+                break;
+
+#if (XUA_USE_SW_PLL)
             /* This is fired when sw_pll has completed initialising a new mclk_rate */
             case inuint_byref(c_sw_pll, u_tmp):
                 printstr("SWPLL synch\n");
 
                 //TODO - hold off audio until we get this ACK
                 break;
-#endif /* ((XUA_SYNCMODE == XUA_SYNCMODE_SYNC) && XUA_USE_SW_PLL) */
+#endif /* (XUA_USE_SW_PLL) */
+#endif /* (XUA_SYNCMODE == XUA_SYNCMODE_SYNC) */
 
 #ifdef IAP
             /* Received word from iap thread - Check for ACK or Data */
diff --git a/lib_xua/src/core/main.xc b/lib_xua/src/core/main.xc
index 901e59bc..85cd0f29 100755
--- a/lib_xua/src/core/main.xc
+++ b/lib_xua/src/core/main.xc
@@ -315,6 +315,9 @@ void usb_audio_io(chanend ?c_aud_in,
 #if (XUA_SPDIF_RX_EN || XUA_ADAT_RX_EN)
     , client interface pll_ref_if i_pll_ref
 #endif
+#if (XUA_SYNCMODE == XUA_SYNCMODE_SYNC)
+    , chanend c_mclk_change
+#endif
 #if ((XUA_SPDIF_RX_EN || XUA_ADAT_RX_EN) && XUA_USE_SW_PLL)
     , port p_for_mclk_count_aud
     , chanend c_sw_pll
@@ -328,7 +331,6 @@ void usb_audio_io(chanend ?c_aud_in,
 #if (XUA_SPDIF_RX_EN || XUA_ADAT_RX_EN)
     chan c_dig_rx;
     chan c_mclk_change; /* Notification of new mclk freq to clockgen */
-
 #if XUA_USE_SW_PLL
     /* Connect p_for_mclk_count_aud to clk_audio_mclk so we can count mclks/timestamp in digital rx*/
 
@@ -381,6 +383,8 @@ void usb_audio_io(chanend ?c_aud_in,
 #endif
 #if (XUA_SPDIF_RX_EN || XUA_ADAT_RX_EN)
                 , c_dig_rx
+#endif                
+#if (XUA_SYNCMODE == XUA_SYNCMODE_SYNC || XUA_SPDIF_RX_EN || XUA_ADAT_RX_EN)
                 , c_mclk_change
 #endif
 #if (XUD_TILE != 0) && (AUDIO_IO_TILE == 0) && (XUA_DFU_EN == 1)
@@ -496,6 +500,9 @@ int main()
 
 #if ((XUA_SYNCMODE == XUA_SYNCMODE_SYNC || XUA_SPDIF_RX_EN || XUA_ADAT_RX_EN) && XUA_USE_SW_PLL)
     chan c_sw_pll;
+#endif
+#if (XUA_SYNCMODE == XUA_SYNCMODE_SYNC)
+    chan c_mclk_change; /* Notification of new mclk freq to ep_buffer */
 #endif
     chan c_sof;
     chan c_xud_out[ENDPOINT_COUNT_OUT];              /* Endpoint channels for XUD */
@@ -589,6 +596,7 @@ int main()
 #endif
                            , c_mix_out
 #if (XUA_SYNCMODE == XUA_SYNCMODE_SYNC)
+                           , c_mclk_change
     #if (!XUA_USE_SW_PLL)
                            , i_pll_ref
     #else
@@ -632,6 +640,9 @@ int main()
 #if (XUA_SPDIF_RX_EN || XUA_ADAT_RX_EN)
                 , i_pll_ref
 #endif
+#if (XUA_SYNCMODE == XUA_SYNCMODE_SYNC)
+                , c_mclk_change
+#endif
 #if ((XUA_SPDIF_RX_EN || XUA_ADAT_RX_EN) && XUA_USE_SW_PLL)
                 , p_for_mclk_count_audio
                 , c_sw_pll