diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 2b0dd1bdc..2496ee28a 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -8,6 +8,8 @@ UNRELEASED
     same functionality as `xua_conf_cores.h` i.e. to allow insertion of tasks
     into the `main()` function (`xua_conf_cores.h` to be deprecated in a future
     release)
+  * ADDED:     Support for lib_sigma_delta to provide high-quality PWM audio
+    outputs via GPIO pins
     ADDED:     Support for define `USER_MAIN_TASKS` with the same functionalty
     as `USER_MAIN_CORES` i.e. to allow insertion of tasks into the `main()`
     function (`USER_MAIN_CORES` to be deprecated in a future release)
diff --git a/lib_xua/api/xua_audiohub.h b/lib_xua/api/xua_audiohub.h
index 70b8036ab..73000d518 100644
--- a/lib_xua/api/xua_audiohub.h
+++ b/lib_xua/api/xua_audiohub.h
@@ -55,7 +55,8 @@
 void XUA_AudioHub(
     NULLABLE_RESOURCE(chanend, c_aud),
     NULLABLE_RESOURCE(clock, clk_audio_mclk),
-    NULLABLE_RESOURCE(clock, clk_audio_bclk), NULLABLE_RESOURCE(in_port_t, p_mclk_in)
+    NULLABLE_RESOURCE(clock, clk_audio_bclk)
+    , NULLABLE_RESOURCE(in_port_t, p_mclk_in)
     , NULLABLE_RESOURCE(i2s_clk_port_type, p_lrclk)
     , NULLABLE_RESOURCE(i2s_clk_port_type, p_bclk)
     , NULLABLE_ARRAY_OF_SIZE(out_buffered_port_32_t, p_i2s_dac, I2S_WIRES_DAC)
@@ -75,6 +76,9 @@ void XUA_AudioHub(
 #if (XUA_NUM_PDM_MICS > 0 || defined(__DOXYGEN__))
     , chanend c_pdm_in
 #endif
+#if (XUA_PWM_CHANNELS > 0) || defined(__DOXYGEN__)
+    , chanend c_pwm_channels
+#endif
 );
 
 void SpdifTxWrapper(chanend c_spdif_tx);
diff --git a/lib_xua/api/xua_conf_default.h b/lib_xua/api/xua_conf_default.h
index cf916105c..9b34e2329 100644
--- a/lib_xua/api/xua_conf_default.h
+++ b/lib_xua/api/xua_conf_default.h
@@ -42,6 +42,13 @@
 #define SPDIF_TX_TILE   AUDIO_IO_TILE
 #endif
 
+/**
+ * @brief Location (tile) of SPDIF Tx. Default: XUD_TILE
+ */
+#ifndef PWM_CHANNELS_TILE
+#define PWM_CHANNELS_TILE   XUD_TILE
+#endif
+
 /**
  * @brief Location (tile) of PDM Rx. Default: AUDIO_IO_TILE
  */
@@ -85,6 +92,27 @@
 #define XUA_NUM_PDM_MICS         (0)
 #endif
 
+/**
+ * @brief Number of PWM output channels in the design. Must be 2 or 0.
+ *
+ * Default: 0
+ */
+#ifndef XUA_NUM_PWM_CHANNELS
+#define XUA_NUM_PWM_CHANNELS     (0)
+#endif
+#if (XUA_NUM_PWM_CHANNELS != 0 && XUA_NUM_PWM_CHANNELS != 2)
+#error "Only none or two PWM channels supported at present"
+#endif
+
+/**
+ * @brief Defines which output channels (stereo) should be output on PWM. Note, Output channels indexed from 0.
+ *
+ * Default: 0 (i.e. channels 0 & 1)
+ * */
+#ifndef PWM_CHANNELS_INDEX
+#define PWM_CHANNELS_INDEX        (0)
+#endif
+
 /**
  * @brief Number of DSD output channels.
  *
@@ -124,6 +152,8 @@
 #define I2S_WIRES_ADC            (I2S_CHANS_ADC / I2S_CHANS_PER_FRAME)
 #endif
 
+#define XUA_I2S_EN ((I2S_WIRES_ADC) > 0 || (I2S_WIRES_DAC) > 0)
+
 /*
  * Defines relating to the interface to external audio hardware i.e. DAC/ADC
  */
diff --git a/lib_xua/api/xua_pwm_conf_default.h b/lib_xua/api/xua_pwm_conf_default.h
new file mode 100644
index 000000000..9af82b933
--- /dev/null
+++ b/lib_xua/api/xua_pwm_conf_default.h
@@ -0,0 +1,42 @@
+// Copyright 2025 XMOS LIMITED.
+// This Software is subject to the terms of the XMOS Public Licence: Version 1.
+#ifndef _xua_pwm_conf_default_h_
+#define _xua_pwm_conf_default_h_
+
+#ifdef __xua_pwm_conf_h_exists__
+    #include "xua_pwm_conf.h"
+#endif
+
+#ifndef XUA_PWM_SD_COEFFS
+#define XUA_PWM_SD_COEFFS     sd_coeffs_o6_f1_5_n8
+#endif
+
+#ifndef XUA_PWM_SCALE
+#define XUA_PWM_SCALE         2.8544
+#endif
+
+#ifndef XUA_PWM_LIMIT
+#define XUA_PWM_LIMIT         2.8684735298
+#endif
+
+#ifndef XUA_PWM_FLAT_COMP_X2
+#define XUA_PWM_FLAT_COMP_X2  (-1.0/29000)
+#endif
+
+#ifndef XUA_PWM_FLAT_COMP_X3
+#define XUA_PWM_FLAT_COMP_X3  (1.0/120000)
+#endif
+
+#ifndef XUA_PWM_PWM_COMP_X2
+#define XUA_PWM_PWM_COMP_X2   (-3.0/190)
+#endif
+
+#ifndef XUA_PWM_PWM_COMP_X3
+#define XUA_PWM_PWM_COMP_X3   (0.63/80)
+#endif
+
+#ifndef XUA_PWM_NEGATE
+#define XUA_PWM_NEGATE        1
+#endif
+
+#endif
diff --git a/lib_xua/lib_build_info.cmake b/lib_xua/lib_build_info.cmake
index e6e2d35ff..2a01244ca 100644
--- a/lib_xua/lib_build_info.cmake
+++ b/lib_xua/lib_build_info.cmake
@@ -28,6 +28,7 @@ set(LIB_OPTIONAL_HEADERS    xua_conf.h
                             xua_conf_cores.h
                             xua_conf_tasks.h
                             static_hid_report.h
+                            xua_pwm_conf.h
                             )
 
 set(LIB_DEPENDENT_MODULES "lib_adat(2.0.1)"
diff --git a/lib_xua/src/core/audiohub/xua_audiohub.xc b/lib_xua/src/core/audiohub/xua_audiohub.xc
index 99fd2c8e0..a2276de39 100755
--- a/lib_xua/src/core/audiohub/xua_audiohub.xc
+++ b/lib_xua/src/core/audiohub/xua_audiohub.xc
@@ -160,7 +160,12 @@ static inline int HandleSampleClock(int frameCount, buffered _XUA_CLK_DIR port:3
 }
 
 #pragma unsafe arrays
-unsigned static AudioHub_MainLoop(chanend ?c_aud, chanend ?c_spd_out
+unsigned static AudioHub_MainLoop(
+    chanend ?c_aud,
+    chanend ?c_spd_out
+#if (XUA_PWM_CHANNELS > 0)
+    , chanend c_pwm_channels
+#endif
 #if (XUA_ADAT_TX_EN)
     , chanend c_adat_out
     , unsigned adatSmuxMode
@@ -409,6 +414,11 @@ unsigned static AudioHub_MainLoop(chanend ?c_aud, chanend ?c_spd_out
                 outuint(c_dig_rx, 0);
 #endif
 
+#if (XUA_PWM_CHANNELS > 0) && (NUM_USB_CHAN_OUT > 0)
+                outuint(c_pwm_channels, samplesOut[PWM_CHANNELS_INDEX]);  /* Forward samples to PWM generator threads */
+                outuint(c_pwm_channels, samplesOut[PWM_CHANNELS_INDEX + 1]);
+#endif
+
 #if (XUA_NUM_PDM_MICS > 0)
                 if ((AUD_TO_MICS_RATIO - 1) == audioToMicsRatioCounter)
                 unsafe {
@@ -603,7 +613,7 @@ void DFUHandler(server interface i_dfu i, chanend ?c_user_cmd);
    connect to the codec ports. It is used during DFU reset and during idle non-streaming mode, if enabled.
    Note there are two paths through depending on dfuMode.*/
 [[combinable]]
-static void dummy_deliver(chanend ?c_aud, unsigned sampFreq, unsigned dfuMode, unsigned &command)
+static void dummy_deliver(chanend ?c_aud, chanend ?c_pwm, unsigned sampFreq, unsigned dfuMode, unsigned &command)
 {
     const int wait_ticks = XS1_TIMER_HZ / sampFreq;
     timer tmr;
@@ -642,6 +652,14 @@ static void dummy_deliver(chanend ?c_aud, unsigned sampFreq, unsigned dfuMode, u
                         /* Process the command in the callee */
                         return;
                     }
+
+#if XUA_PWM_CHANNELS > 0
+#pragma loop unroll
+                    for(int i = 0; i < XUA_PWM_CHANNELS; i++)
+                    {
+                        outuint(c_pwm, 0);
+                    }
+#endif
                 }
                 /* Wait one sample period */
                 tmr when timerafter(tmr_trigger) :> void;
@@ -657,7 +675,6 @@ static void dummy_deliver(chanend ?c_aud, unsigned sampFreq, unsigned dfuMode, u
     }
 }
 
-
 #if XUA_DFU_EN
 /* External DFU handler task */
 [[distributable]]
@@ -667,7 +684,7 @@ void DFUHandler(server interface i_dfu i, chanend ?c_user_cmd);
 /* Helper function to see if a request for entry to DFU has been issued via a sample rate change.
    If so, enter DFU. Note this code will never return. The device will
    need to be reset which is part of the DFU sequence */
-void check_and_enter_dfu(unsigned curSamFreq, chanend c_aud, server interface i_dfu ?dfuInterface)
+void check_and_enter_dfu(unsigned curSamFreq, chanend c_aud, chanend ?c_pwm, server interface i_dfu ?dfuInterface)
 {
     /* Currently no more audio will happen after this point */
     if ((curSamFreq / AUD_TO_USB_RATIO) == AUDIO_STOP_FOR_DFU)
@@ -691,7 +708,7 @@ void check_and_enter_dfu(unsigned curSamFreq, chanend c_aud, server interface i_
                 DFUHandler(dfuInterface, null);
 #endif
                 /* This never exits because we set DFU mode*/
-                dummy_deliver(c_aud, 48000, 1, command);
+                dummy_deliver(c_aud, c_pwm, 48000, 1, command);
             }
             /* Note, we shouldn't reach here. Audio, once stopped for DFU, cannot be resumed */
         }
@@ -700,8 +717,12 @@ void check_and_enter_dfu(unsigned curSamFreq, chanend c_aud, server interface i_
 #endif /* XUA_DFU_EN */
 
 
-void XUA_AudioHub(chanend ?c_aud, clock ?clk_audio_mclk, clock ?clk_audio_bclk,
-    in port ?p_mclk_in,
+#if(XUA_PWM_CHANNELS == 0)
+#define c_pwm_channels null
+#endif
+
+void XUA_AudioHub(chanend ?c_aud, clock ?clk_audio_mclk, clock ?clk_audio_bclk
+    , in port ?p_mclk_in,
     buffered _XUA_CLK_DIR port:32 ?p_lrclk,
     buffered _XUA_CLK_DIR port:32 ?p_bclk,
     buffered out port:32 (&?p_i2s_dac)[I2S_WIRES_DAC],
@@ -721,6 +742,9 @@ void XUA_AudioHub(chanend ?c_aud, clock ?clk_audio_mclk, clock ?clk_audio_bclk,
 #if (XUA_NUM_PDM_MICS > 0)
     , chanend c_pdm_in
 #endif
+#if (XUA_PWM_CHANNELS > 0) || defined(__DOXYGEN__)
+    , chanend c_pwm_channels
+#endif
 )
 {
 /* This is a bit annoying but we have a mixture of nullable interfaces and variadic function signatures based on defines */
@@ -766,10 +790,10 @@ void XUA_AudioHub(chanend ?c_aud, clock ?clk_audio_mclk, clock ?clk_audio_bclk,
                 firstRun = 0;
             }
             /* Now run dummy loop with no IO. This is sufficient to poll for commands from decouple */
-            dummy_deliver(c_aud, 1000, 0, command);  /* Run loop at 1kHz for min power and exit if command */
+            dummy_deliver(c_aud, c_pwm_channels, 1000, 0, command);  /* Run loop at 1kHz for min power and exit if command */
             receive_command(command, c_aud, curSamFreq, dsdMode, curSamRes_DAC, audioActive);
 #if (XUA_DFU_EN == 1)
-            check_and_enter_dfu(curSamFreq, c_aud, dfuInterface);
+            check_and_enter_dfu(curSamFreq, c_aud, c_pwm_channels, dfuInterface);
 #endif /* (XUA_DFU_EN == 1) */
         } /* audioActive == 0 */
 
@@ -979,6 +1003,11 @@ void XUA_AudioHub(chanend ?c_aud, clock ?clk_audio_mclk, clock ?clk_audio_bclk,
                 }
 #endif
                 {
+#if (XUA_PWM_CHANNELS > 0)
+                    /* Communicate master clock and sample freq to PWM thread */
+                    outct(c_pwm_channels, XS1_CT_END);
+                    outuint(c_pwm_channels, curSamFreq);
+#endif
 #if (XUA_SPDIF_TX_EN)
                     /* Communicate master clock and sample freq to S/PDIF thread */
                     outct(c_spdif_out, XS1_CT_END);
@@ -1005,6 +1034,9 @@ void XUA_AudioHub(chanend ?c_aud, clock ?clk_audio_mclk, clock ?clk_audio_bclk,
 #else
                        , null
 #endif
+#if (XUA_PWM_CHANNELS > 0)
+                   , c_pwm_channels
+#endif
 #if (XUA_ADAT_TX_EN)
                        , c_adat_out
                        , adatSmuxMode
@@ -1022,8 +1054,7 @@ void XUA_AudioHub(chanend ?c_aud, clock ?clk_audio_mclk, clock ?clk_audio_bclk,
                     /* Now perform any additional inputs and update state accordingly */
                     receive_command(command, c_aud, curSamFreq, dsdMode, curSamRes_DAC, audioActive);
 #if (XUA_DFU_EN == 1)
-                    check_and_enter_dfu(curSamFreq, c_aud, dfuInterface);
-
+                    check_and_enter_dfu(curSamFreq, c_aud, c_pwm_channels, dfuInterface);
 #endif /* (XUA_DFU_EN == 1) */
 #endif /* XUA_USB_EN */
 
diff --git a/lib_xua/src/core/clocking/sw_pll_wrapper.xc b/lib_xua/src/core/clocking/sw_pll_wrapper.xc
index 168ef66e5..c9fa9cedb 100644
--- a/lib_xua/src/core/clocking/sw_pll_wrapper.xc
+++ b/lib_xua/src/core/clocking/sw_pll_wrapper.xc
@@ -120,7 +120,7 @@ void sw_pll_task(chanend c_sw_pll){
        the first control value has been received. This avoids issues with
        channel lockup if two tasks (eg. init and SDM) try to write at the same time. */
 
-    unsigned command = inuint(c_sw_pll);
+    inuint(c_sw_pll);
     inct(c_sw_pll);
     while(1)
     {
diff --git a/lib_xua/src/core/endpoint0/xua_ep0_descriptors.h b/lib_xua/src/core/endpoint0/xua_ep0_descriptors.h
index ca5879f79..fa02c43be 100644
--- a/lib_xua/src/core/endpoint0/xua_ep0_descriptors.h
+++ b/lib_xua/src/core/endpoint0/xua_ep0_descriptors.h
@@ -14,6 +14,7 @@
 #include "descriptor_defs.h"
 #include "usbaudio20.h"                /* Defines from the USB Audio 2.0 Specifications */
 #include "usbaudiocommon.h"
+#include "packet_sizes.h"
 #include "xud_device.h"
 #include "xua_hid_descriptor.h"
 #include "xua_ep0_midi_descriptors.h"
diff --git a/lib_xua/src/core/main.xc b/lib_xua/src/core/main.xc
index 05942ac62..f5fead548 100644
--- a/lib_xua/src/core/main.xc
+++ b/lib_xua/src/core/main.xc
@@ -13,6 +13,7 @@
 #include <platform.h>
 #include <xs1.h>
 #include <xclib.h>
+#include <stdio.h>
 #include <print.h>
 #ifdef XSCOPE
 #include <xscope.h>
@@ -29,6 +30,10 @@
 #include "spdif.h"                     /* From lib_spdif */
 #endif
 
+#if (XUA_PWM_CHANNELS > 0)
+#include "pwm_thread.h"
+#endif
+
 #if (XUA_ADAT_RX_EN)
 #include "adat_rx.h"
 #endif
@@ -105,6 +110,7 @@ on tile[AUDIO_IO_TILE] : buffered in port:32 p_i2s_adc[I2S_WIRES_ADC] =
     #define p_i2s_adc null
 #endif
 
+#if XUA_I2S_EN
 
 #if CODEC_MASTER
 on tile[AUDIO_IO_TILE] : buffered in port:32 p_lrclk        = PORT_I2S_LRCLK;
@@ -113,6 +119,10 @@ on tile[AUDIO_IO_TILE] : buffered in port:32 p_bclk         = PORT_I2S_BCLK;
 on tile[AUDIO_IO_TILE] : buffered out port:32 p_lrclk       = PORT_I2S_LRCLK;
 on tile[AUDIO_IO_TILE] : buffered out port:32 p_bclk        = PORT_I2S_BCLK;
 #endif
+#else
+#define p_lrclk null
+#define p_bclk null
+#endif
 
 #if (MCLK_REQUIRED)
 /* Audio master clock input */
@@ -168,6 +178,10 @@ on tile[MIDI_TILE] :  buffered in port:1 p_midi_rx          = PORT_MIDI_IN;
 #endif
 
 
+#if (XUA_PWM_CHANNELS > 0)
+clock clk_pwm_channels                                      = on tile[PWM_CHANNELS_TILE]: CLKBLK_PWM;
+#endif
+
 #ifdef MIDI
 on tile[MIDI_TILE] : clock    clk_midi                      = CLKBLK_MIDI;
 #endif
@@ -266,6 +280,9 @@ void usb_audio_io(chanend ?c_aud_in,
 #if (XUA_SPDIF_TX_EN) && (SPDIF_TX_TILE != AUDIO_IO_TILE)
     chanend c_spdif_tx,
 #endif
+#if (XUA_PWM_CHANNELS > 0)
+    chanend c_pwm_channels,
+#endif
 #if (MIXER)
     chanend c_mix_ctl,
 #endif
@@ -307,6 +324,10 @@ void usb_audio_io(chanend ?c_aud_in,
 #endif /* (XUA_SPDIF_RX_EN || XUA_ADAT_RX_EN) */
 
 
+#if (XUA_PWM_CHANNELS > 0) && (PWM_CHANNELS_TILE == AUDIO_IO_TILE)
+    pwm_init(p_mclk_in);
+#endif
+
 #if (XUA_SPDIF_TX_EN) && (SPDIF_TX_TILE == AUDIO_IO_TILE)
     chan c_spdif_tx;
 
@@ -354,6 +375,9 @@ void usb_audio_io(chanend ?c_aud_in,
 #endif
 #if (XUA_NUM_PDM_MICS > 0)
                 , c_pdm_pcm
+#endif
+#if (XUA_PWM_CHANNELS > 0)
+                , c_pwm_channels
 #endif
             );
         }
@@ -438,6 +462,10 @@ int main()
     chan c_spdif_tx;
 #endif
 
+#if (XUA_PWM_CHANNELS > 0)
+    chan c_pwm_channels;
+#endif
+
 #if (XUA_SPDIF_RX_EN || XUA_ADAT_RX_EN)
     chan c_clk_ctl;
     chan c_clk_int;
@@ -531,6 +559,9 @@ int main()
 
                 /* Attach mclk count port to mclk clock-block (for feedback) */
                 //set_port_clock(p_for_mclk_count, clk_audio_mclk);
+#if (XUA_PWM_CHANNELS > 0) && (PWM_CHANNELS_TILE != AUDIO_IO_TILE)
+                pwm_init(p_mclk_in);
+#endif
 #if(SECOND_MCLK_REQUIRED)
                 set_clock_src(clk_audio_mclk_usb, p_mclk_in_usb);
                 set_port_clock(p_for_mclk_count, clk_audio_mclk_usb);
@@ -610,6 +641,9 @@ int main()
 #if (XUA_SPDIF_TX_EN) && (SPDIF_TX_TILE != AUDIO_IO_TILE)
                 , c_spdif_tx
 #endif
+#if (XUA_PWM_CHANNELS > 0)
+                , c_pwm_channels
+#endif
 #if (MIXER)
                 , c_mix_ctl
 #endif
@@ -642,7 +676,23 @@ int main()
         }
 #endif
 
+#if (XUA_PWM_CHANNELS > 0)
+        on tile[PWM_CHANNELS_TILE]:
+        {
+            thread_speed();
+            timer tmr;
+            int tt;
+            tmr :> tt;
+            // Nasty - wait for clock block to be inited
+            // Ideally, this happens before the PAR.
+            // But it is inside the IO thread
+            tmr when timerafter(tt + 1000000) :> void;
+            pwm_thread(c_pwm_channels);
+        }
+#endif
+
 #ifdef MIDI
+
         /* MIDI core */
         on tile[MIDI_TILE]:
         {
diff --git a/lib_xua/src/core/ports/audioports.c b/lib_xua/src/core/ports/audioports.c
index 6f018998e..59312708a 100644
--- a/lib_xua/src/core/ports/audioports.c
+++ b/lib_xua/src/core/ports/audioports.c
@@ -41,8 +41,15 @@ void ConfigAudioPortsWrapper(
     port p_adc[], int numPortsAdc,
 #endif
 
-    port p_lrclk,
-    port p_bclk,
+#if (I2S_CHANS_DAC != 0) || (I2S_CHANS_ADC != 0)
+#if (CODEC_MASTER == 0)
+    NULLABLE_RESOURCE(out_buffered_port_32_t, p_lrclk),
+    out_buffered_port_32_t p_bclk,
+#else
+    NULLABLE_RESOURCE(in_buffered_port_32_t, p_lrclk),
+    in_buffered_port_32_t p_bclk,
+#endif
+#endif
     NULLABLE_RESOURCE(in_port_t,  p_mclk_in),
     clock clk_audio_bclk, unsigned int divide, unsigned curSamFreq)
 {
@@ -55,8 +62,11 @@ void ConfigAudioPortsWrapper(
             p_adc,
             numPortsAdc,
 #endif
+#if (I2S_CHANS_DAC != 0) || (I2S_CHANS_ADC != 0)
             p_lrclk,
             p_bclk,
-            p_mclk_in, clk_audio_bclk, divide, curSamFreq);
+#endif
+            p_mclk_in,
+            clk_audio_bclk, divide, curSamFreq);
 }
 
diff --git a/lib_xua/src/core/ports/audioports.h b/lib_xua/src/core/ports/audioports.h
index ed3f019c6..dc0c4f088 100644
--- a/lib_xua/src/core/ports/audioports.h
+++ b/lib_xua/src/core/ports/audioports.h
@@ -17,16 +17,19 @@ void ConfigAudioPorts(
     in_buffered_port_32_t p_i2s_adc[],
     int numAdcPorts,
 #endif
+#if (I2S_CHANS_DAC != 0) || (I2S_CHANS_ADC != 0)
 #if (CODEC_MASTER == 0)
     NULLABLE_RESOURCE(out_buffered_port_32_t, p_lrclk),
     out_buffered_port_32_t p_bclk,
 #else
     NULLABLE_RESOURCE(in_port_t, p_lrclk),
     in_port_t p_bclk,
+#endif
 #endif
     NULLABLE_RESOURCE(in_port_t,  p_mclk_in),
     clock clk_audio_bclk, unsigned int divide, unsigned int curSamFreq);
 
+
 void DeConfigAudioPorts(
 #if (I2S_CHANS_DAC != 0) || (DSD_CHANS_DAC != 0)
     out_buffered_port_32_t p_i2s_dac[],
@@ -47,7 +50,6 @@ void DeConfigAudioPorts(
     clock clk_audio_bclk);
 
 
-
 void ConfigAudioPortsWrapper(
 #if (I2S_CHANS_DAC != 0) || (DSD_CHANS_DAC != 0)
     out_buffered_port_32_t p_i2s_dac[],
@@ -57,12 +59,14 @@ void ConfigAudioPortsWrapper(
     in_buffered_port_32_t  p_i2s_adc[],
     int numPortsADC,
 #endif
+#if (I2S_CHANS_DAC != 0) || (I2S_CHANS_ADC != 0)
 #if (CODEC_MASTER == 0)
     NULLABLE_RESOURCE(out_buffered_port_32_t, p_lrclk),
     out_buffered_port_32_t p_bclk,
 #else
     NULLABLE_RESOURCE(in_buffered_port_32_t, p_lrclk),
     in_buffered_port_32_t p_bclk,
+#endif
 #endif
     NULLABLE_RESOURCE(in_port_t,  p_mclk_in),
     clock clk_audio_bclk, unsigned int divide, unsigned curSamFreq);
diff --git a/lib_xua/src/core/ports/audioports.xc b/lib_xua/src/core/ports/audioports.xc
index c1350b3d1..959879ddf 100644
--- a/lib_xua/src/core/ports/audioports.xc
+++ b/lib_xua/src/core/ports/audioports.xc
@@ -17,12 +17,14 @@ void ConfigAudioPorts(
     int numPortsAdc,
 #endif
 
+#if (I2S_CHANS_DAC != 0) || (I2S_CHANS_ADC != 0)
 #if (CODEC_MASTER == 0)
     buffered out port:32 ?p_lrclk,
     buffered out port:32 p_bclk,
 #else
     in port ?p_lrclk,
     in port p_bclk,
+#endif
 #endif
     in port ?p_mclk_in,
     clock clk_audio_bclk, unsigned int divide, unsigned curSamFreq)
diff --git a/lib_xua/src/core/pwm_thread.c b/lib_xua/src/core/pwm_thread.c
new file mode 100644
index 000000000..6106fb588
--- /dev/null
+++ b/lib_xua/src/core/pwm_thread.c
@@ -0,0 +1,52 @@
+// Copyright 2024-2025 XMOS LIMITED.
+// This Software is subject to the terms of the XMOS Public Licence: Version 1.
+/**
+ * @file    pwm_thread.c
+ * @brief   Fork the threads to run a PWM engine
+ * @author  Henk Muller, XMOS Semiconductor Ltd
+ */
+#include "xua_conf_default.h" // Settings
+#if (XUA_PWM_CHANNELS > 0)
+#include "xua_pwm_conf_default.h" // PWM Settings
+#include <platform.h>
+#include <xcore/port.h>
+#include <xcore/chanend.h>
+#include <xcore/clock.h>
+#include "software_dac_hp.h"
+#include "sigma_delta_modulators.h"
+#include "uac_hwresources.h"
+
+void setup_master_clock(port_t clk_in) __attribute__ ((weak));
+void setup_master_clock(port_t clk_in) {
+}
+
+void pwm_init(port_t clk_in) {
+    xclock_t clk = CLKBLK_PWM;
+    setup_master_clock(clk_in);
+    port_set_invert(clk_in);
+    clock_enable(clk);
+    clock_set_source_port(clk, clk_in);
+}
+
+void pwm_thread(chanend_t c_data)
+{
+    software_dac_hp_t sd;
+    xclock_t clk = CLKBLK_PWM;
+    port_t ports[2] = {PORT_PWM_OUT_LEFT, PORT_PWM_OUT_RIGHT};
+    port_t clk_out = PORT_PWM_CLK_OUT;
+
+    software_dac_hp_init(&sd, ports, clk, clk_out, 8,
+                         XUA_PWM_SD_COEFFS,
+                         XUA_PWM_SCALE,
+                         XUA_PWM_LIMIT,
+                         XUA_PWM_FLAT_COMP_X2,
+                         XUA_PWM_FLAT_COMP_X3,
+                         XUA_PWM_PWM_COMP_X2,
+                         XUA_PWM_PWM_COMP_X3,
+                         XUA_PWM_NEGATE);
+    software_dac_hp(&sd, c_data);
+}
+#endif
+
+
+
diff --git a/lib_xua/src/core/pwm_thread.h b/lib_xua/src/core/pwm_thread.h
new file mode 100644
index 000000000..037596da3
--- /dev/null
+++ b/lib_xua/src/core/pwm_thread.h
@@ -0,0 +1,22 @@
+// Copyright 2024-2025 XMOS LIMITED.
+// This Software is subject to the terms of the XMOS Public Licence: Version 1.
+#ifndef __pwm_thread__h_
+#define __pwm_thread__h_
+
+#include "xua_conf_default.h" // Settings
+
+#if (XUA_PWM_CHANNELS > 0)
+  #ifdef __XC__
+    void pwm_init(in port clk_in);
+    void pwm_thread(chanend c_data);
+  #else
+    #include <xcore/chanend.h>
+    void pwm_init(port_t clk_in);
+    void pwm_thread(chanend_t c_data);
+  #endif
+#endif
+
+#endif
+
+
+
diff --git a/lib_xua/src/core/uac_hwresources.h b/lib_xua/src/core/uac_hwresources.h
index 4cd6cdf7d..db6799ba5 100644
--- a/lib_xua/src/core/uac_hwresources.h
+++ b/lib_xua/src/core/uac_hwresources.h
@@ -11,5 +11,6 @@
 #define CLKBLK_FLASHLIB    XS1_CLKBLK_3   /* Clock block for use by flash lib */
 #define CLKBLK_ADAT_RX     XS1_CLKBLK_REF /* Use REF for ADAT_RX on x200/AI series */
 #define CLKBLK_I2S_BIT     XS1_CLKBLK_3
+#define CLKBLK_PWM         XS1_CLKBLK_1
 
 #endif /* _UAC_HWRESOURCES_H_ */