xmos · shuchitak · Feb 5, 2026 · Feb 3, 2026 · Feb 4, 2026 · Feb 4, 2026
diff --git a/CHANGELOG.rst b/CHANGELOG.rst
@@ -1,21 +1,24 @@
 lib_mic_array change log
 ========================
 
-UNRELEASED
-----------
+6.0.0
+-----
 
-  * ADDED: A new API to replace vanilla that is the default recommended way
-    of using the mic array.
-  * ADDED: Support for mic array shutdown which causes the mic arry thread(s)
+  * ADDED: A new API to replace vanilla that is the default recommended way of
+    using the mic array.
+  * ADDED: Support for mic array shutdown which causes the mic array thread(s)
     to return.
   * ADDED: Test for mic array shutdown
   * ADDED: API to support initialising the mic array with custom decimation
     filters
   * CHANGED: BasicMicArray tests to test the default API
   * CHANGED: app_measure_mips example to run the default API
   * CHANGED: Documentation improvements
+  * CHANGED: replaced assert.h with xcore/assert.h
   * FIXED: PDM RX ISR deadlock bug
   * REMOVED: Vanilla API and configuration
+  * REMOVED: Prefab API
+  * REMOVED: lib_xassert dependency
 
 5.5.0
 -----

diff --git a/README.rst b/README.rst
@@ -6,7 +6,7 @@ lib_mic_array: PDM microphone array library
 ###########################################
 
 :vendor: XMOS
-:version: 5.5.0
+:version: 6.0.0
 :scope: General Use
 :description: PDM microphone array library
 :category: Audio

diff --git a/doc/rst/src/examples.rst b/doc/rst/src/examples.rst
@@ -1,4 +1,6 @@
 
+.. _examples:
+
 ********
 Examples
 ********

diff --git a/doc/rst/src/introduction.rst b/doc/rst/src/introduction.rst
@@ -3,19 +3,20 @@
 Introduction
 ************
 
-``lib_mic_array`` is a library for interfacing with one or more PDM microphones
-on an XMOS device.
+``lib_mic_array`` provides microphone array processing support on XMOS devices.
+It interfaces with one or more PDM (Pulse Density Modulation) microphones, capturing and converting their
+output into high-quality PCM audio suitable for downstream voice and audio
+processing pipelines.
 
-Version 5.0 of this library has been redesigned from scratch to leverage the
-`Vector unit in the XMOS XS3 architecture <https://www.xmos.com/documentation/XM-014007-PS/html/doc/rst/xs3-arch-inst.html#vector-unit>`_.
+PDM microphones produce a high-rate, 1-bit digital bitstream. The library
+captures these PDM streams on the device and performs the required filtering
+and decimation to produce 32-bit PCM audio samples.
 
-See :ref:`using_mic_array` to get started.
+For high level description of mic array processing and the library capabilities, refer to :ref:`overview`.
+To get started with using the library, see :ref:`using_mic_array` and :ref:`examples`.
 
-.. note::
-
-  Version 5.0 does not currently support XS2 or XS1 devices. Please use version 4.5.0 if you need support for these devices: https://github.com/xmos/lib_mic_array/releases/tag/v4.5.0
 
+.. note::
 
-Find the latest version of ``lib_mic_array`` on `GitHub
-<https://github.com/xmos/lib_mic_array>`_.
+  From Version 5.0 onwards, the library does not support XS2 or XS1 devices. Please use version 4.5.0 if you need support for these devices: https://github.com/xmos/lib_mic_array/releases/tag/v4.5.0
 
diff --git a/doc/rst/src/overview.rst b/doc/rst/src/overview.rst
@@ -1,4 +1,6 @@
 
+.. _overview:
+
 ********
 Overview
 ********

diff --git a/examples/app_custom_filter/src/app_i2s.c b/examples/app_custom_filter/src/app_i2s.c
@@ -11,7 +11,7 @@
 #include <xcore/channel_streaming.h>
 #include <stdint.h>
 #include <stdio.h>
-#include <assert.h>
+#include <xcore/assert.h>
 #include <stdlib.h>
 #include <string.h>
 #include <platform.h>

diff --git a/examples/app_custom_filter/src/main.xc b/examples/app_custom_filter/src/main.xc
@@ -8,7 +8,6 @@
 #include <stdio.h>
 #include <stdint.h>
 #include <string.h>
-#include <assert.h>
 #include "xk_voice_l71/board.h"
 #include "app_config.h"
 #include "mic_array.h"

diff --git a/examples/app_mic_array/src/app_i2s.c b/examples/app_mic_array/src/app_i2s.c
@@ -11,7 +11,7 @@
 #include <xcore/channel_streaming.h>
 #include <stdint.h>
 #include <stdio.h>
-#include <assert.h>
+#include <xcore/assert.h>
 #include <stdlib.h>
 #include <string.h>
 #include <platform.h>

diff --git a/examples/app_mic_array/src/main.xc b/examples/app_mic_array/src/main.xc
@@ -8,7 +8,6 @@
 #include <stdio.h>
 #include <stdint.h>
 #include <string.h>
-#include <assert.h>
 #include "xk_voice_l71/board.h"
 #include "app_config.h"
 #include "mic_array.h"

diff --git a/examples/app_par_decimator/src/app_i2s.c b/examples/app_par_decimator/src/app_i2s.c
@@ -11,7 +11,7 @@
 #include <xcore/channel_streaming.h>
 #include <stdint.h>
 #include <stdio.h>
-#include <assert.h>
+#include <xcore/assert.h>
 #include <stdlib.h>
 #include <string.h>
 #include <platform.h>

diff --git a/examples/app_par_decimator/src/main.xc b/examples/app_par_decimator/src/main.xc
@@ -8,7 +8,6 @@
 #include <stdio.h>
 #include <stdint.h>
 #include <string.h>
-#include <assert.h>
 #include "app_config.h"
 
 #include "app.h"

diff --git a/examples/app_shutdown/src/app_i2s.c b/examples/app_shutdown/src/app_i2s.c
@@ -3,7 +3,7 @@
 
 #include <stdint.h>
 #include <stdio.h>
-#include <assert.h>
+#include <xcore/assert.h>
 #include <stdlib.h>
 #include <string.h>
 #include <math.h>

diff --git a/examples/app_shutdown/src/main.xc b/examples/app_shutdown/src/main.xc
@@ -8,7 +8,6 @@
 #include <stdio.h>
 #include <stdint.h>
 #include <string.h>
-#include <assert.h>
 #include "xk_voice_l71/board.h"
 #include "app_config.h"
 #include "mic_array.h"

diff --git a/examples/deps.cmake b/examples/deps.cmake
@@ -14,5 +14,4 @@ endif()
 
 set(APP_DEPENDENT_MODULES   "lib_mic_array"
                             "i2s"
-                            "lib_xassert"
-                            "lib_board_support(develop)")
+                            "lib_board_support(1.5.0)")
diff --git a/lib_mic_array/api/mic_array/etc/filters_default.h b/lib_mic_array/api/mic_array/etc/filters_default.h
@@ -15,20 +15,17 @@ C_API_START
  * @brief Macro indicating Stage 1 Decimation Factor
  *
  * This is the ratio of input sample rate to output sample rate for the first
- * filter stage.
+ * filter stage. This value is fixed, even when using custom filter coefficients.
  *
- * @note In version 5.0 of lib_mic_array, this value is fixed (even if you
- * choose not to use the default filter coefficients).
  */
 #define STAGE1_DEC_FACTOR   32
 
 /**
  * @brief Macro indicating Stage 1 Filter Tap Count
  *
  * This is the number of filter taps in the first stage filter.
+ * This value is fixed, even when using custom filter coefficients.
  *
- * @note In version 5.0 of lib_mic_array, this value is fixed (even if you
- * choose not to use the default filter coefficients).
  */
 #define STAGE1_TAP_COUNT    256
 

diff --git a/lib_mic_array/api/mic_array/etc/xcore_compat.h b/lib_mic_array/api/mic_array/etc/xcore_compat.h
@@ -4,8 +4,8 @@
 #pragma once
 
 /**
- * The `<xcore/>` headers cannot be safely included from XC files, but 
- * several of the types defined in those headers need to be available in XC. 
+ * The `<xcore/>` headers cannot be safely included from XC files, but
+ * several of the types defined in those headers need to be available in XC.
  * This header is a work-around which defines those types for XC but includes
  * them for C or CPP files.
  */
@@ -22,7 +22,7 @@ extern "C" {
     unsigned end_a;
     unsigned end_b;
   } streaming_channel_t;
-  
+
   typedef struct {
     unsigned end_a;
     unsigned end_b;

diff --git a/lib_mic_array/api/mic_array/mic_array_task.h b/lib_mic_array/api/mic_array/mic_array_task.h
@@ -20,12 +20,15 @@ C_API_START
  * is not created (when running in thread context) so the received PDM samples are
  * ignored.
  *
- * @param pdm_res     Pointer to the pdm_rx_resources_t struct containing hardware resources
- *                    required by the mic array module.
- * @param channel_map Array containing MIC_ARRAY_CONFIG_MIC_IN_COUNT to MIC_ARRAY_CONFIG_MIC_COUNT mapping.
- *                    array dimension should be MIC_ARRAY_CONFIG_MIC_COUNT, and the i<sup>th</sup> entry is the
- *                    input pdm pin index mapped to mic array output index i
- * @param output_samp_freq output PCM sampling frequency (supported values are 16, 32 and 48KHz)
+ * @param pdm_res           Pointer to the pdm_rx_resources_t struct containing hardware resources
+ *                          required by the mic array module.
+ * @param channel_map       Optional mapping from PDM input pin to mic-array output channel index.
+ *                          - Array size: MIC_ARRAY_CONFIG_MIC_COUNT
+ *                          - channel_map[i] is the PDM pin index that should feed mic output channel i.
+ *                          - If channel_map is NULL, a default 1:1 mapping is used: PDM pin i -> mic output channel i.
+ *                          - Valid values for channel_map[i] are in [0, MIC_ARRAY_CONFIG_MIC_IN_COUNT-1].
+ * @param output_samp_freq  Target sampling rate (in Hz) for the decimated PCM output stream
+ *                          Supported values: 16000, 32000, 48000 (Hz).
  */
 MA_C_API
 void mic_array_init(pdm_rx_resources_t *pdm_res, const unsigned *channel_map, unsigned output_samp_freq);

diff --git a/lib_mic_array/api/mic_array/pdm_resources.h b/lib_mic_array/api/mic_array/pdm_resources.h
@@ -2,12 +2,12 @@
 // This Software is subject to the terms of the XMOS Public Licence: Version 1.
 #pragma once
 
+#include <stdio.h> // for clock_t
+#include <stdint.h>
 #include "api.h"
 #include "etc/xcore_compat.h"
 
-#include "xmath/xmath.h"
 
-#include <stdint.h>
 
 
 C_API_START

diff --git a/lib_mic_array/lib_build_info.cmake b/lib_mic_array/lib_build_info.cmake
@@ -1,7 +1,6 @@
 set(LIB_NAME lib_mic_array)
-set(LIB_VERSION 5.5.0)
-set(LIB_DEPENDENT_MODULES "lib_xcore_math(2.4.0)"
-                           "lib_xassert(4.3.2)")
+set(LIB_VERSION 6.0.0)
+set(LIB_DEPENDENT_MODULES "lib_xcore_math(2.4.0)")
 set(LIB_INCLUDES
     api
     api/mic_array

diff --git a/lib_mic_array/module_build_info b/lib_mic_array/module_build_info
@@ -1,7 +1,6 @@
-VERSION = 5.5.0
+VERSION = 6.0.0
 
-DEPENDENT_MODULES = lib_xcore_math(>=2.4.0) \
-                    lib_xassert(>=4.3.2)
+DEPENDENT_MODULES = lib_xcore_math(>=2.4.0)
 
 MODULE_XCC_FLAGS = $(XCC_FLAGS) -g -Os
 

diff --git a/lib_mic_array/src/frame_transfer.c b/lib_mic_array/src/frame_transfer.c
@@ -17,15 +17,7 @@ unsigned ma_frame_tx(
     const unsigned sample_count)
 {
   unsigned shutdown = 0;
-#if 0
-  transacting_chanend_t ct_frame = chan_init_transaction_master(c_frame_out);
-  t_chan_out_buf_word(&ct_frame,
-                      (uint32_t*) frame,
-                      channel_count * sample_count);
-  chan_complete_transaction(ct_frame);
-#else
   chanend_out_control_token(c_frame_out, XS1_CT_END);
-  //asm volatile("testct %0, res[%1]" : "=r"(shutdown) : "r"(c_frame_out));
   shutdown = chanend_test_control_token_next_byte(c_frame_out);
   if(shutdown)
   {
@@ -41,8 +33,6 @@ unsigned ma_frame_tx(
     chanend_out_control_token(c_frame_out, XS1_CT_END); // close the channel only when not shutting down
     chanend_check_control_token(c_frame_out, XS1_CT_END);
   }
-
-#endif
   return shutdown;
 }
 
@@ -52,22 +42,13 @@ void ma_frame_rx(
     const unsigned channel_count,
     const unsigned sample_count)
 {
-#if 0
-  transacting_chanend_t ct_frame = chan_init_transaction_slave(c_frame_in);
-  t_chan_in_buf_word(&ct_frame,
-                     (uint32_t*) frame,
-                     channel_count * sample_count);
-  chan_complete_transaction(ct_frame);
-#else
   chanend_check_control_token(c_frame_in, XS1_CT_END);
   chanend_out_byte(c_frame_in, 0); //dummy indicating wish to proceed with data transfer
   for(int i=0; i<channel_count*sample_count; i++) {
     frame[i] = chanend_in_word(c_frame_in);
   }
   chanend_check_control_token(c_frame_in, XS1_CT_END);
   chanend_out_control_token(c_frame_in, XS1_CT_END);
-
-#endif
 }
 
 
@@ -77,15 +58,6 @@ void ma_frame_rx_transpose(
     const unsigned channel_count,
     const unsigned sample_count)
 {
-#if 0
-  transacting_chanend_t ct_frame = chan_init_transaction_slave(c_frame_in);
-  for(int ch = 0; ch < channel_count; ch++){
-    for(int smp = 0; smp < sample_count; smp++){
-      frame[smp*channel_count+ch] = t_chan_in_word(&ct_frame);
-    }
-  }
-  chan_complete_transaction(ct_frame);
-#else
   chanend_check_control_token(c_frame_in, XS1_CT_END);
   chanend_out_byte(c_frame_in, 0); //dummy indicating wish to proceed with data transfer
 
@@ -96,10 +68,9 @@ void ma_frame_rx_transpose(
   }
   chanend_check_control_token(c_frame_in, XS1_CT_END);
   chanend_out_control_token(c_frame_in, XS1_CT_END);
-#endif
 }
 
-void ma_shutdown(const chanend_t c_frame_in) //same chanend as whats used in ma_frame_rx()
+void ma_shutdown(const chanend_t c_frame_in) //same chanend as the one used in ma_frame_rx()
 {
   chanend_check_control_token(c_frame_in, XS1_CT_END);
   chanend_out_control_token(c_frame_in, XS1_CT_END); // indicate shutdown to ma_frame_tx()

diff --git a/lib_mic_array/src/mic_array_setup.c b/lib_mic_array/src/mic_array_setup.c
@@ -45,30 +45,35 @@ void mic_array_resources_configure(
   port_clear_buffer(pdm_res->p_pdm_mics);
 }
 
+static inline
+void mic_array_inpw8(const port_t p_pdm_mics)
+{
+  uint32_t tmp;
+  asm volatile("inpw %0, res[%1], 8" : "=r"(tmp)
+                    : "r" (p_pdm_mics));
+}
 
 void mic_array_pdm_clock_start(
     pdm_rx_resources_t* pdm_res)
 {
   if( pdm_res->clock_b != 0 ) {
-    uint32_t tmp;
-
+
     port_clear_buffer(pdm_res->p_pdm_mics);
-    
+
     /* start the faster capture clock */
     clock_start(pdm_res->clock_b);
 
     /* wait for a rising edge on the capture clock */
-    // (this ensures the rising edges of the two 
+    // (this ensures the rising edges of the two
     //  clocks are not in phase)
-    asm volatile("inpw %0, res[%1], 8" : "=r"(tmp) 
-                    : "r" (pdm_res->p_pdm_mics));
+    mic_array_inpw8(pdm_res->p_pdm_mics);
 
     /* start the slower output clock */
     clock_start(pdm_res->clock_a);
   } else {
     // You'd think that we could move the `clock_start(pdm_res->clock_a)` to be
-    //  after the if..else block instead of duplicating it. But no, if I try 
-    //  that, the compiler screws something up and the output audio is all 
+    //  after the if..else block instead of duplicating it. But no, if I try
+    //  that, the compiler screws something up and the output audio is all
     //  messed up.
     clock_start(pdm_res->clock_a);
   }