#include "devicedefines.h" #if (NUM_PDM_MICS > 0) /* This file includes an example integration of lib_array_mic into USB Audio */ #include #include #include #include #include #include #include #include "fir_decimator.h" #include "mic_array.h" /* Hardware resources */ in port p_pdm_clk = PORT_PDM_CLK; in buffered port:32 p_pdm_mics = PORT_PDM_DATA; in port p_mclk = PORT_PDM_MCLK; clock pdmclk = on tile[PDM_TILE]: XS1_CLKBLK_3; /* User hooks */ unsafe void user_pdm_process(frame_audio * unsafe audio, int output[]); void user_pdm_init(); int data_0[4*COEFS_PER_PHASE*MAX_DECIMATION_FACTOR] = {0}; int data_1[4*COEFS_PER_PHASE*MAX_DECIMATION_FACTOR] = {0}; frame_audio mic_audio[2]; void pdm_process(streaming chanend c_ds_output_0, streaming chanend c_ds_output_1, chanend c_audio) { unsigned buffer = 1; // Buffer index memset(mic_audio, sizeof(frame_audio), 0); int output[NUM_PDM_MICS]; user_pdm_init(); while(1) { unsigned samplerate; c_audio :> samplerate; unsigned decimationfactor = 48000/samplerate; unsafe { decimator_config_common dcc = {FRAME_SIZE_LOG2, 1, 0, 0, decimationfactor, fir_coefs[decimationfactor], 0}; decimator_config dc0 = {&dcc, data_0, {0, 0, 0, 0}}; decimator_config dc1 = {&dcc, data_1, {0, 0, 0, 0}}; decimator_configure(c_ds_output_0, c_ds_output_1, dc0, dc1); } decimator_init_audio_frame(c_ds_output_0, c_ds_output_1, buffer, mic_audio, DECIMATOR_NO_FRAME_OVERLAP); while(1) { frame_audio * unsafe current = decimator_get_next_audio_frame(c_ds_output_0, c_ds_output_1, buffer, mic_audio); unsafe { int req; user_pdm_process(current, output); c_audio :> req; if(req) { for(int i = 0; i < NUM_PDM_MICS; i++) { c_audio <: output[i]*decimationfactor; } } else { break; } } } } } #if MAX_FREQ > 48000 #error MAX_FREQ > 48000 NOT CURRENTLY SUPPORTED #endif void pcm_pdm_mic(chanend c_pcm_out) { streaming chan c_4x_pdm_mic_0, c_4x_pdm_mic_1; streaming chan c_ds_output_0, c_ds_output_1; /* TODO, always run mics at 3MHz */ configure_clock_src_divide(pdmclk, p_mclk, 2); configure_port_clock_output(p_pdm_clk, pdmclk); configure_in_port(p_pdm_mics, pdmclk); start_clock(pdmclk); par { pdm_rx(p_pdm_mics, c_4x_pdm_mic_0, c_4x_pdm_mic_1); decimate_to_pcm_4ch(c_4x_pdm_mic_0, c_ds_output_0); decimate_to_pcm_4ch(c_4x_pdm_mic_1, c_ds_output_1); pdm_process(c_ds_output_0, c_ds_output_1, c_pcm_out); } } #endif