PDM function rename and PDM buffer tidy

module_usb_audio/pdm_mics/pdm_mic.xc

@@ -14,7 +14,7 @@
 #include <stdint.h>
 
 #include "mic_array.h"
-#include "pcm_pdm_mic.h"
+#include "xua_pdm_mic.h"
 
 #define MAX_DECIMATION_FACTOR 12
 
@@ -30,14 +30,15 @@ int data_1[4*THIRD_STAGE_COEFS_PER_STAGE * MAX_DECIMATION_FACTOR] = {0};
 mic_array_frame_time_domain mic_audio[2];
 
 [[combinable]]
-void pdm_process(streaming chanend c_ds_output[2], chanend c_audio
+void pdm_buffer(streaming chanend c_ds_output[2], chanend c_audio
 #ifdef MIC_PROCESSING_USE_INTERFACE
    , client mic_process_if i_mic_process
 #endif
 )
 {
-    unsigned buffer = 1;     // Buffer index
+    unsigned buffer;     
     int output[NUM_PDM_MICS];
+    unsigned samplerate;
 
 #ifdef MIC_PROCESSING_USE_INTERFACE
     i_mic_process.init();
@@ -50,13 +51,10 @@ void pdm_process(streaming chanend c_ds_output[2], chanend c_audio
     mic_array_frame_time_domain * unsafe current; 
     mic_array_decimator_config_t dc[2]; 
 
-    unsigned samplerate;
+    /* Get initial sample-rate and compute decimation factor */ 
-
     c_audio :> samplerate;
-
     unsigned decimationfactor = 96000/samplerate;
 
-
     unsafe
     {
         fir_coefs[0] = 0;
@@ -117,6 +115,7 @@ void pdm_process(streaming chanend c_ds_output[2], chanend c_audio
         {
             case c_audio :> req:
                     
+                /* Audio IO core requests samples */
                 if(req)
                 unsafe{
                     for(int i = 0; i < NUM_PDM_MICS; i++)
@@ -124,10 +123,10 @@ void pdm_process(streaming chanend c_ds_output[2], chanend c_audio
                         c_audio <: output[i];
                     }
 
-                        
+                    /* Get a new frame of mic data */    
                     mic_array_frame_time_domain * unsafe current = mic_array_get_next_time_domain_frame(c_ds_output, 2, buffer, mic_audio, dc);
 
-
+                    /* Run user code */
 #ifdef MIC_PROCESSING_USE_INTERFACE
                     i_mic_process.transfer_buffers(current, output);
 #else
@@ -138,15 +137,19 @@ void pdm_process(streaming chanend c_ds_output[2], chanend c_audio
                 unsafe{
                     /* Sample rate change */
                     c_audio :> samplerate;
+                    
+                    /* Re-config the mic decimators for the new sample-rate */
                     decimationfactor = 96000/samplerate;
                     dcc.output_decimation_factor = decimationfactor;
                     dcc.coefs=fir_coefs[decimationfactor/2];
-                        mic_array_decimator_configure(c_ds_output, 2, dc);
                     
+                    mic_array_decimator_configure(c_ds_output, 2, dc);
                     mic_array_init_time_domain_frame(c_ds_output, 2, buffer, mic_audio, dc);
 
+                    /* Get a new mic data frame */
                     mic_array_frame_time_domain * unsafe current = mic_array_get_next_time_domain_frame(c_ds_output, 2, buffer, mic_audio, dc);
 
+                    /* Run user code */
 #ifdef MIC_PROCESSING_USE_INTERFACE
                     i_mic_process.transfer_buffers(current, output);
 #else
@@ -154,15 +157,15 @@ void pdm_process(streaming chanend c_ds_output[2], chanend c_audio
 #endif
                 }
                 break;
-        }
+        } /* select */
-    }
+    } /* while(1) */
 }
 
 #if MAX_FREQ > 48000
 #error MAX_FREQ > 48000 NOT CURRENTLY SUPPORTED
 #endif
 
-void pcm_pdm_mic(streaming chanend c_ds_output[2])
+void pdm_mic(streaming chanend c_ds_output[2])
 {
     streaming chan c_4x_pdm_mic_0, c_4x_pdm_mic_1;
 
@@ -172,20 +175,12 @@ void pcm_pdm_mic(streaming chanend c_ds_output[2])
     configure_in_port(p_pdm_mics, pdmclk);
     start_clock(pdmclk);
 
-    unsafe
-    {
     par
     {
         mic_array_pdm_rx(p_pdm_mics, c_4x_pdm_mic_0, c_4x_pdm_mic_1);
         mic_array_decimate_to_pcm_4ch(c_4x_pdm_mic_0, c_ds_output[0]);
         mic_array_decimate_to_pcm_4ch(c_4x_pdm_mic_1, c_ds_output[1]);
-//#ifdef MIC_PROCESSING_USE_INTERFACE
+    }
-//        pdm_process(c_ds_output, c_pcm_out, i_mic_process);
-///        /* Note: user_pdm process is included in main.xc to allow maximum flexibilty for customisation/distribution etc */
-//#else
-//        pdm_process(c_ds_output, c_pcm_out);
-//#endif
-    }}
 }
 
 #endif

module_usb_audio/pdm_mics/xua_pdm_mic.h

@@ -5,16 +5,13 @@
 /* Interface based user processing */
 typedef interface mic_process_if
 {
-    //[[guarded]]
-    //void transfer_buffers(int * unsafe in_mic_buf, int * unsafe in_spk_buf, int * unsafe out_mic_buf, int * unsafe out_spk_buf);
     void transfer_buffers(mic_array_frame_time_domain * unsafe audio, int output[]);
-
     void init();
 } mic_process_if;
 
 
 [[combinable]]
-void pdm_process(streaming chanend c_ds_output[2], chanend c_audio
+void pdm_buffer(streaming chanend c_ds_output[2], chanend c_audio
 #ifdef MIC_PROCESSING_USE_INTERFACE
    , client mic_process_if i_mic_process
 #endif
@@ -23,8 +20,8 @@ void pdm_process(streaming chanend c_ds_output[2], chanend c_audio
 [[combinable]]
 void user_pdm_process(server mic_process_if i_mic_data);
 
-
+/* PDM interface and decimation cores */
-void pcm_pdm_mic(streaming chanend c_ds_output[2]);
+void pdm_mic(streaming chanend c_ds_output[2]);
 
 #else
 
@@ -33,7 +30,8 @@ unsafe void user_pdm_process(mic_array_frame_time_domain * unsafe audio, int out
 
 void user_pdm_init();
 
-void pcm_pdm_mic(streaming chanend c_ds_output[2]);
+/* PDM interface and decimation cores */
+void pdm_mic(streaming chanend c_ds_output[2]);
 
 #endif