Feature/rebased pwm

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)

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);

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
  */

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

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)"

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 */
 

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)
     {

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"