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Support for PDM and I2S to be on same tile; MCLK divider set to 4 to generate PDM clk

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This commit is contained in:
Krishna Balan
2015-12-17 17:17:52 +00:00
parent 12ec473470
commit bf75f409f7
1 changed files with 15 additions and 2 deletions
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17
module_usb_audio/pdm_mics/pcm_pdm_mic.xc
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@@ -19,8 +19,12 @@
/* Hardware resources */
in port p_pdm_clk = PORT_PDM_CLK;
in buffered port:32 p_pdm_mics = PORT_PDM_DATA;
#if AUDIO_IO_TILE != PDM_TILE
in port p_mclk = PORT_PDM_MCLK;
clock pdmclk = on tile[PDM_TILE]: XS1_CLKBLK_3;
#else
// Use 'p_mclk_in' shared by I2S
#endif
clock pdmclk = on tile[PDM_TILE]: XS1_CLKBLK_4;
/* User hooks */
unsafe void user_pdm_process(frame_audio * unsafe audio, int output[]);
@@ -92,9 +96,18 @@ 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);
/* Assuming MCLK is 24.576 MHz */
#if AUDIO_IO_TILE != PDM_TILE
configure_clock_src_divide(pdmclk, p_mclk, 4);
#else
unsigned port_id, divide = 4;
asm("ldw %0, dp[p_mclk_in]":"=r"(port_id));
asm("setclk res[%0], %1"::"r"(pdmclk), "r"(port_id));
asm("setd res[%0], %1"::"r"(pdmclk), "r"(divide));
#endif
configure_port_clock_output(p_pdm_clk, pdmclk);
configure_in_port(p_pdm_mics, pdmclk);
start_clock(pdmclk);