xmos · shuchitak · Jun 26, 2024 · Jun 21, 2024 · Jun 25, 2024 · Jun 25, 2024
diff --git a/CHANGELOG.rst b/CHANGELOG.rst
@@ -1,6 +1,13 @@
 lib_src change log
 ==================
 
+3.0.0
+-----
+
+  * FIXED: Double buffer asrc_io.input_timestamp to prevent producer timestamp
+    getting overwritten during asrc processing
+  * REMOVED: xscope_used argument from the asynchronous_fifo_producer_put() API
+
 2.5.0
 -----
 

diff --git a/doc/asrc_task/asrc_task.rst b/doc/asrc_task/asrc_task.rst
@@ -25,7 +25,7 @@ The ASRC Task supports the following nominal sample rates for input and output:
     - 88.2 kHz
     - 96 kHz
     - 176.4 kHz
-    - 192 kHz 
+    - 192 kHz
 
 Because the required compute for multi-channel systems may exceed the performance limit of a single thread, the ASRC subsystem is able to make use of multiple threads in parallel to achieve the required conversion within the sample time period. It uses a dynamic fork and join architecture to share the ASRC workload across multiple threads each time a batch of samples is processed. The threads must all reside on the same tile as the ASRC task due to them sharing input and output buffers. The workload and buffer partitioning is dynamically computed by the ASRC task at stream startup and is constrained by the user at compile time to set maximum limits of both channel count and worker threads.
 
@@ -40,7 +40,7 @@ The difference between the performance requirement between the two architectures
 
     - An eight channel system consisting of either 44.1kHz or 48kHz input with maximum output rate of 192kHz will require about (0.15 * (48 + 192) * 8) ~= 288 thread MHz. This can adequately be provided by four threads (assuming up to 8 active threads on an xcore.ai device with a 600MHz clock).
 
-In reality the amount of thread MHz needed will be lower than the above formulae suggest since subsequent ASRC channels after the first can share some of the calculations. This results in about at 10% performance requirement reduction per additional channel per worker thread. Increasing the input frame size in the ASRC task may also reduce the MHz requirement a few % at the cost of larger buffers and a slight latency increase. 
+In reality the amount of thread MHz needed will be lower than the above formulae suggest since subsequent ASRC channels after the first can share some of the calculations. This results in about at 10% performance requirement reduction per additional channel per worker thread. Increasing the input frame size in the ASRC task may also reduce the MHz requirement a few % at the cost of larger buffers and a slight latency increase.
 
 .. warning::
     Exceeding the processing time available by specifying a channel count, input/output rates, number of worker threads or device clock speed may result in at best choppy audio or a blocked ASRC task if the overrun is persistent.
@@ -102,7 +102,7 @@ An example of the user-defined `C` function for receiving the input samples is s
 
         // Receive stream info from producer
         *new_input_rate = chanend_in_word(c_producer);
-        asrc_io->input_timestamp = chanend_in_word(c_producer);
+        asrc_io->input_timestamp[asrc_io->input_write_idx] = chanend_in_word(c_producer);
         asrc_io->input_channel_count = chanend_in_word(c_producer);
 
         // Pack into array properly LRLRLRLR or 123412341234 etc.

diff --git a/lib_src/api/asynchronous_fifo.h b/lib_src/api/asynchronous_fifo.h
@@ -59,7 +59,7 @@ typedef struct asynchronous_fifo_t_ {
  * The ``state`` argument should be an int64_t array of
  * ``ASYNCHRONOUS_FIFO_INT64_ELEMENTS`` elements that is cast to
  * ``asynchronous_fifo_t*``.
- * 
+ *
  * That pointer should also be used for all other operations, including operations
  * both the consumer and producer sides.
  *
@@ -177,8 +177,6 @@ void asynchronous_fifo_exit(asynchronous_fifo_t * UNSAFE state);
  *
  * @param   timestamp           The number of ticks when this sample was input.
  *
- * @param   xscope_used         Set to 1 if the PID values should be output over
- *                              xscope. Used for debugging. This parameter is subject to be removed in future revisions.
  *
  * @returns The current estimate of the mismatch of input and output frequencies.
  *          This is represented as a 32-bit signed number. Zero means no mismatch,
@@ -193,8 +191,7 @@ void asynchronous_fifo_exit(asynchronous_fifo_t * UNSAFE state);
 int32_t asynchronous_fifo_producer_put(asynchronous_fifo_t * UNSAFE state,
                                        int32_t * UNSAFE samples,
                                        int n,
-                                       int32_t timestamp,
-                                       int xscope_used);
+                                       int32_t timestamp);
 
 
 /**

diff --git a/lib_src/lib_build_info.cmake b/lib_src/lib_build_info.cmake
@@ -1,5 +1,5 @@
 set(LIB_NAME lib_src)
-set(LIB_VERSION 2.5.0)
+set(LIB_VERSION 3.0.0)
 
 set(LIB_DEPENDENT_MODULES "lib_logging(3.2.0)")
 

diff --git a/lib_src/module_build_info b/lib_src/module_build_info
@@ -1,4 +1,4 @@
-VERSION = 2.5.0
+VERSION = 3.0.0
 
 DEPENDENT_MODULES = lib_logging(>=3.2.0)
 

diff --git a/lib_src/src/asrc_task/asrc_task.c b/lib_src/src/asrc_task/asrc_task.c
@@ -82,7 +82,7 @@ void do_asrc_group(schedule_info_t *schedule, uint64_t fs_ratio, asrc_in_out_t *
     // Pack into the frame this instance of ASRC expects
     int input_samples[ASRC_N_IN_SAMPLES * MAX_ASRC_CHANNELS_TOTAL];
     for(int i = 0; i < ASRC_N_IN_SAMPLES * num_worker_channels; i++){
-        // int rd_idx = i % num_worker_channels + (i / num_worker_channels) * asrc_io->asrc_channel_count + worker_channel_start_idx; 
+        // int rd_idx = i % num_worker_channels + (i / num_worker_channels) * asrc_io->asrc_channel_count + worker_channel_start_idx;
         int rd_idx = i + (asrc_io->asrc_channel_count - num_worker_channels) * (i / num_worker_channels) + worker_channel_start_idx; // Optimisation of above
         input_samples[i] = asrc_io->input_samples[input_write_idx][rd_idx];
     }
@@ -193,13 +193,13 @@ void reset_asrc_fifo_consumer(asynchronous_fifo_t * fifo){
 }
 
 // Default implementation of receive (called from ASRC) which receives samples and config over a channel. This is overridable.
-ASRC_TASK_ISR_CALLBACK_ATTR 
+ASRC_TASK_ISR_CALLBACK_ATTR
 unsigned receive_asrc_input_samples_cb_default(chanend_t c_asrc_input, asrc_in_out_t *asrc_io, unsigned *new_input_rate){
     static unsigned asrc_in_counter = 0;
 
     // Get format and timing data from channel
     *new_input_rate = chanend_in_word(c_asrc_input);
-    asrc_io->input_timestamp = chanend_in_word(c_asrc_input);
+    asrc_io->input_timestamp[asrc_io->input_write_idx] = chanend_in_word(c_asrc_input);
     asrc_io->input_channel_count = chanend_in_word(c_asrc_input);
 
     // Pack into array properly LRLRLRLR for 2ch or 123412341234 for 4ch etc.
@@ -232,7 +232,7 @@ DEFINE_INTERRUPT_CALLBACK(ASRC_ISR_GRP, asrc_samples_rx_isr_handler, app_data){
     chanend_t c_buff_idx = asrc_receive_samples_ctx->c_buff_idx;
     asrc_in_out_t *asrc_io = asrc_receive_samples_ctx->asrc_io;
     ASRC_TASK_ISR_CALLBACK_ATTR asrc_task_produce_isr_cb_t receive_asrc_input_samples_cb = asrc_io->asrc_task_produce_cb;
-    
+
     // Always consume samples so we don't apply backpressure to the producer
     // Call the user defined receive samples callback.
     ASRC_TASK_ISR_CALLBACK_ATTR
@@ -242,7 +242,7 @@ DEFINE_INTERRUPT_CALLBACK(ASRC_ISR_GRP, asrc_samples_rx_isr_handler, app_data){
     if(asrc_in_counter == 0 && asrc_io->ready_flag_to_receive){
         // Note if you ever find the code has stopped here then this is due to the time required to ASRC process the input frame
         // is longer than the period of the frames coming in. To remedy this you need to increase ASRC processing resources or reduce
-        // the processing requirement. If you are using XCORE-200, consider using xcore.ai for more than 2x the ASRC performance. 
+        // the processing requirement. If you are using XCORE-200, consider using xcore.ai for more than 2x the ASRC performance.
         // Notify ASRC main loop of new frame
         chanend_out_byte(c_buff_idx, (uint8_t)asrc_io->input_write_idx);
         asrc_io->input_write_idx ^= 1; // Swap buffers
@@ -274,7 +274,7 @@ static inline void asrc_wait_for_valid_config(chanend_t c_buff_idx, uint32_t *in
 
 // Check to see if input params have changed since last process
 static inline bool asrc_detect_format_change(uint32_t input_frequency, uint32_t output_frequency, asrc_in_out_t *asrc_io){
-    if( asrc_io->input_frequency != input_frequency || 
+    if( asrc_io->input_frequency != input_frequency ||
         asrc_io->input_channel_count != asrc_io->asrc_channel_count ||
         asrc_io->output_frequency != output_frequency){
 
@@ -291,7 +291,7 @@ DEFINE_INTERRUPT_PERMITTED(ASRC_ISR_GRP, void, asrc_processor,
                             asrc_in_out_t *asrc_io,
                             chanend_t c_buff_idx,
                             asynchronous_fifo_t * fifo){
-    
+
     uint32_t input_frequency = 0;   // Set to invalid for now. We will get rates supplied by producer and consumer.
     uint32_t output_frequency = 0;
 
@@ -304,7 +304,7 @@ DEFINE_INTERRUPT_PERMITTED(ASRC_ISR_GRP, void, asrc_processor,
         {  2268, 2268, 1134, 1134,  567,  567},
         {  2083, 2083, 1042, 1042,  521,  521}
     };
-    
+
     // Setup a pointer to a struct so the ISR can access these elements
     asrc_receive_samples_ctx_t asrc_receive_samples_ctx = {c_asrc_input, c_buff_idx, asrc_io};
 
@@ -322,7 +322,7 @@ DEFINE_INTERRUPT_PERMITTED(ASRC_ISR_GRP, void, asrc_processor,
         int inputFsCode = frequency_to_fs_code(input_frequency);
         int outputFsCode = frequency_to_fs_code(output_frequency);
         int interpolation_ticks = interpolation_ticks_2D[inputFsCode][outputFsCode];
-        
+
         //// FIFO init
         dprintf("FIFO init channels: %d length: %ld\n", asrc_io->asrc_channel_count, fifo->max_fifo_depth);
         asynchronous_fifo_init(fifo, asrc_io->asrc_channel_count, fifo->max_fifo_depth);
@@ -367,8 +367,6 @@ DEFINE_INTERRUPT_PERMITTED(ASRC_ISR_GRP, void, asrc_processor,
         ideal_fs_ratio = (fs_ratio + (1<<31)) >> 32;
         dprintf("ideal_fs_ratio: %d\n", ideal_fs_ratio);
 
-        const int xscope_used = 0; // Vestige of ASRC API. TODO - cleanup in future when lib_src is tidied
-
         asrc_io->ready_flag_to_receive = 1; // Signal we are ready to consume a frame of input samples
         asrc_io->ready_flag_configured = 1; // SIgnal we are ready to produce
 
@@ -385,10 +383,10 @@ DEFINE_INTERRUPT_PERMITTED(ASRC_ISR_GRP, void, asrc_processor,
 
             int32_t t0 = get_reference_time();
             int num_output_samples = par_asrc(num_jobs, schedule, fs_ratio, asrc_io, input_write_idx, sASRCCtrl);
-            int ts = asrc_timestamp_interpolation(asrc_io->input_timestamp, sASRCCtrl[0], interpolation_ticks);
+            int ts = asrc_timestamp_interpolation(asrc_io->input_timestamp[input_write_idx], sASRCCtrl[0], interpolation_ticks);
             // Only push to FIFO if we have samples (FIFO has a bug) otherwise hold last error value
             if(num_output_samples){
-                error = asynchronous_fifo_producer_put(fifo, &asrc_io->output_samples[0], num_output_samples, ts, xscope_used);
+                error = asynchronous_fifo_producer_put(fifo, &asrc_io->output_samples[0], num_output_samples, ts);
             }
 
             fs_ratio = (((int64_t)ideal_fs_ratio) << 32) + (error * (int64_t) ideal_fs_ratio);
@@ -409,7 +407,7 @@ DEFINE_INTERRUPT_PERMITTED(ASRC_ISR_GRP, void, asrc_processor,
 }
 
 
-// Wrapper to setup ISR->task signalling chanend and use ISR friendly call to function 
+// Wrapper to setup ISR->task signalling chanend and use ISR friendly call to function
 void asrc_task(chanend_t c_asrc_input, asrc_in_out_t *asrc_io, asynchronous_fifo_t *fifo, unsigned fifo_length){
     // Check callback is init'd. If not, use default implementation.
     if (asrc_io->asrc_task_produce_cb == NULL){

diff --git a/lib_src/src/asrc_task/asrc_task.h b/lib_src/src/asrc_task/asrc_task.h
@@ -27,7 +27,7 @@
     #define SRC_DITHER_SETTING                  0
 
 #else
-    // Check for required static defines    
+    // Check for required static defines
     #include "asrc_task_config.h"
 
     #ifndef     MAX_ASRC_CHANNELS_TOTAL
@@ -53,7 +53,7 @@
 #endif
 
 /** @brief Decorator for user ASRC producer receive callback. Must be used to allow stack usage calculation. */
-#define  ASRC_TASK_ISR_CALLBACK_ATTR            __attribute__((fptrgroup("asrc_callback_isr_fptr_grp"))) 
+#define  ASRC_TASK_ISR_CALLBACK_ATTR            __attribute__((fptrgroup("asrc_callback_isr_fptr_grp")))
 
 #ifndef __DOXYGEN__
 
@@ -90,11 +90,11 @@ typedef struct asrc_in_out_t_{
     int32_t input_samples[2][ASRC_N_IN_SAMPLES * MAX_ASRC_CHANNELS_TOTAL];
     /** Double buffer idx */
     unsigned input_write_idx;
-    /** Timestamp of last received input sample */                                        
-    int32_t input_timestamp;
-    /** Nominal input sample rate  44100..192000 (set by producer) */  
+    /** Timestamp of last received input sample. Double buffered */
+    int32_t input_timestamp[2];
+    /** Nominal input sample rate  44100..192000 (set by producer) */
     unsigned input_frequency;
-    /** This is set by the producer and can change dynamically */                                           
+    /** This is set by the producer and can change dynamically */
     unsigned input_channel_count;
     /** The function pointer of the ASRC_TASK producer receive callback. Must be defined by user to receive samples from producer over channel. */
     void * UNSAFE asrc_task_produce_cb;
@@ -111,7 +111,7 @@ typedef struct asrc_in_out_t_{
     unsigned asrc_channel_count;
     /** Flag to indicate ASRC ready to accept samples */
     int ready_flag_to_receive;
-    /** Flag to indicate ASRC is configured and OK to pull from FIFO */                                               
+    /** Flag to indicate ASRC is configured and OK to pull from FIFO */
     int ready_flag_configured;
 
 }asrc_in_out_t;
@@ -161,9 +161,9 @@ void reset_asrc_fifo_consumer(asynchronous_fifo_t * UNSAFE fifo);
  * Prototype that can optionally be defined by the user to initialise the function pointer for the ASRC receive produced samples ISR.
  * If this is not called then receive_asrc_input_samples_cb_default() is used and the you may call send_asrc_input_samples_default()
  * from the application to send samples to the ASRC task.
- * 
+ *
  * Must be called before running asrc_task()
- * 
+ *
  * \param asrc_io           A pointer to the structure used for holding ASRC IO and state.
  * \param asrc_rx_fp        A pointer to the user asrc_receive_samples function. NOTE - This MUST be decorated by ASRC_TASK_ISR_CALLBACK_ATTR
  *                          to allow proper stack calculation by the compiler. See receive_asrc_input_samples_cb_default() in asrc_task.c
@@ -176,7 +176,7 @@ void init_asrc_io_callback(asrc_in_out_t * UNSAFE asrc_io, asrc_task_produce_isr
 /**
  * If the init_asrc_io_callback() function is not called then a default implementation of the ASRC receive will be used.
  * This send function (called by the user producer side) mirrors the receive and can be used to push samples into the ASRC.
- * 
+ *
  * \param c_asrc_input          The chan end on the application producer side connecting to the ASRC task.
  * \param input_frequency       The sample rate of the input stream (44100, 48000, ...).
  * \param input_timestamp       The ref clock timestamp of latest received input sample.

diff --git a/lib_src/src/asynchronous_fifo.c b/lib_src/src/asynchronous_fifo.c
@@ -110,8 +110,7 @@ void asynchronous_fifo_reset_consumer(asynchronous_fifo_t *state) {
 
 int32_t asynchronous_fifo_producer_put(asynchronous_fifo_t *state, int32_t *samples,
                                   int n,
-                                  int32_t timestamp,
-                                  int xscope_used) {
+                                  int32_t timestamp) {
     int read_ptr = state->read_ptr;
     int write_ptr = state->write_ptr;
     int max_fifo_depth = state->max_fifo_depth;
@@ -160,21 +159,17 @@ int32_t asynchronous_fifo_producer_put(asynchronous_fifo_t *state, int32_t *samp
             state->frequency_ratio +=
                 (diff_error  * (int64_t) (state->Kp / n)) +  // TODO: make this lookup table
                 (phase_error * (int64_t) state->Ki);
-            if (xscope_used) {
-#if defined(ASYNC_FIFO_XSCOPE_INSTRUMENTATION)            
+#if defined(ASYNC_FIFO_XSCOPE_INSTRUMENTATION)
                 xscope_int(1, phase_error);
                 xscope_int(2, diff_error);
 #endif
-            }
         }
         state->last_phase_error = phase_error;
     }
-    if (xscope_used) {
-#if defined(ASYNC_FIFO_XSCOPE_INSTRUMENTATION)            
+#if defined(ASYNC_FIFO_XSCOPE_INSTRUMENTATION)
         xscope_int(3, len);
         xscope_int(4, state->frequency_ratio >> K_SHIFT);
 #endif
-    }
     return (state->frequency_ratio + (1<<(K_SHIFT-1))) >> K_SHIFT;
 }
 

diff --git a/settings.yml b/settings.yml
@@ -1,7 +1,7 @@
 ---
 project: lib_src
 title: SAMPLE RATE CONVERSION
-version: 2.5.0
+version: 3.0.0
 
 documentation:
   exclude_patterns_path: doc/exclude_patterns.inc

diff --git a/tests/asrc_task_test/asrc_task_receive_samples.c b/tests/asrc_task_test/asrc_task_receive_samples.c
@@ -9,7 +9,7 @@ unsigned receive_asrc_input_samples(chanend_t c_producer, asrc_in_out_t *asrc_io
 
     // Receive stream info from producer
     *new_input_rate = chanend_in_word(c_producer);
-    asrc_io->input_timestamp = chanend_in_word(c_producer);
+    asrc_io->input_timestamp[asrc_io->input_write_idx] = chanend_in_word(c_producer);
     asrc_io->input_channel_count = chanend_in_word(c_producer);
 
     // Pack into array properly LRLRLRLR or 123412341234 etc.
@@ -29,4 +29,4 @@ unsigned receive_asrc_input_samples(chanend_t c_producer, asrc_in_out_t *asrc_io
 // Register the above function for ASRC task
 void setup_asrc_io_custom_callback(asrc_in_out_t *asrc_io){
     init_asrc_io_callback(asrc_io, receive_asrc_input_samples);
-}
+}
diff --git a/tests/asynchronous_fifo_asrc_test/Makefile b/tests/asynchronous_fifo_asrc_test/Makefile
@@ -1,7 +1,7 @@
 TARGET = XCORE-AI-EXPLORER
 APP_NAME =
 USED_MODULES = lib_src
-XCC_FLAGS = -O3 -fxscope -DASYNC_FIFO_XSCOPE_INSTRUMENTATION
+XCC_FLAGS = -O3 -fxscope
 
 include $(XMOS_MAKE_PATH)/xcommon/module_xcommon/build/Makefile.common