Merge pull request #385 from ed-xmos/feature/guard_adat_tx

Add ADAT Tx guard for framecount is zero

CHANGELOG.rst

@@ -7,6 +7,7 @@ UNRELEASED
   * FIXED:     Device fails to enumerate when ADAT and S/PDIF transmit are enabled
   * CHANGED:   Enable only the minimum number of ADAT input formats based for the
     supported sample frequencies
+  * FIXED:     ADAT Tx called too frequently
 
 4.0.0
 -----

lib_xua/src/core/audiohub/xua_audiohub.xc

@@ -375,12 +375,11 @@ unsigned static AudioHub_MainLoop(chanend ?c_out, chanend ?c_spd_out
                 }
 #endif // (I2S_CHANS_DAC != 0)
 
-#if (XUA_ADAT_TX_EN)
-                 TransferAdatTxSamples(c_adat_out, samplesOut, adatSmuxMode, 1);
-#endif
-
             if(frameCount == 0)
             {
+#if (XUA_ADAT_TX_EN)
+                TransferAdatTxSamples(c_adat_out, samplesOut, adatSmuxMode, 1);
+#endif
 
 #if (XUA_SPDIF_RX_EN || XUA_ADAT_RX_EN)
                 /* Sync with clockgen */