Merge pull request #317 from FrankBoesing/spdif

Spdif-input

Audio.h

@@ -98,6 +98,7 @@
 #include "input_tdm.h"
 #include "input_tdm2.h"
 #include "input_pdm.h"
+#include "input_spdif3.h"
 #include "mixer.h"
 #include "output_dac.h"
 #include "output_dacs.h"

input_spdif3.cpp

@@ -0,0 +1,253 @@
+/* Audio Library for Teensy 3.X
+ * Copyright (c) 2019, Paul Stoffregen, paul@pjrc.com
+ *
+ * Development of this audio library was funded by PJRC.COM, LLC by sales of
+ * Teensy and Audio Adaptor boards.  Please support PJRC's efforts to develop
+ * open source software by purchasing Teensy or other PJRC products.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice, development funding notice, and this permission
+ * notice shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+/*
+ by Frank Bösing
+ */
+
+#if defined(__IMXRT1052__) || defined(__IMXRT1062__)
+#include <Arduino.h>
+#include "input_spdif3.h"
+#include "output_spdif3.h"
+#include "utility/imxrt_hw.h"
+
+DMAMEM __attribute__((aligned(32)))
+static uint32_t spdif_rx_buffer[AUDIO_BLOCK_SAMPLES * 4];
+audio_block_t * AudioInputSPDIF3::block_left = NULL;
+audio_block_t * AudioInputSPDIF3::block_right = NULL;
+uint16_t AudioInputSPDIF3::block_offset = 0;
+bool AudioInputSPDIF3::update_responsibility = false;
+DMAChannel AudioInputSPDIF3::dma(false);
+
+FLASHMEM
+void AudioInputSPDIF3::begin(void)
+{
+	dma.begin(true); // Allocate the DMA channel first
+
+	AudioOutputSPDIF3::config_spdif3();
+
+	const int nbytes_mlno = 2 * 4; // 8 Bytes per minor loop
+	dma.TCD->SADDR = &SPDIF_SRL;
+	dma.TCD->SOFF = 4;
+	dma.TCD->ATTR = DMA_TCD_ATTR_SSIZE(2) | DMA_TCD_ATTR_DSIZE(2);
+	dma.TCD->NBYTES_MLNO = DMA_TCD_NBYTES_MLOFFYES_NBYTES(nbytes_mlno) | DMA_TCD_NBYTES_SMLOE |
+                         DMA_TCD_NBYTES_MLOFFYES_MLOFF(-8);
+	dma.TCD->SLAST = -8;
+	dma.TCD->DADDR = spdif_rx_buffer;
+	dma.TCD->DOFF = 4;
+	dma.TCD->DLASTSGA = -sizeof(spdif_rx_buffer);
+	dma.TCD->CITER_ELINKNO = sizeof(spdif_rx_buffer) / nbytes_mlno;
+	dma.TCD->BITER_ELINKNO = sizeof(spdif_rx_buffer) / nbytes_mlno;
+	dma.TCD->CSR = DMA_TCD_CSR_INTHALF | DMA_TCD_CSR_INTMAJOR;
+
+	dma.triggerAtHardwareEvent(DMAMUX_SOURCE_SPDIF_RX);
+	update_responsibility = update_setup();
+	dma.attachInterrupt(isr);
+	dma.enable();
+
+	SPDIF_SRCD = 0;
+	SPDIF_SCR |= SPDIF_SCR_DMA_RX_EN;
+	CORE_PIN15_CONFIG = 3;
+	IOMUXC_SPDIF_IN_SELECT_INPUT = 0; // GPIO_AD_B1_03_ALT3
+	//pinMode(13, OUTPUT);
+}
+
+void AudioInputSPDIF3::isr(void)
+{
+	uint32_t daddr, offset;
+	const int32_t *src, *end;
+	int16_t *dest_left, *dest_right;
+	audio_block_t *left, *right;
+
+	dma.clearInterrupt();
+	//digitalWriteFast(13, !digitalReadFast(13));
+	if (AudioInputSPDIF3::update_responsibility) AudioStream::update_all();
+
+	daddr = (uint32_t)(dma.TCD->DADDR);
+
+	if (daddr < (uint32_t)spdif_rx_buffer + sizeof(spdif_rx_buffer) / 2) {
+		// DMA is receiving to the first half of the buffer
+		// need to remove data from the second half
+		src = (int32_t *)&spdif_rx_buffer[AUDIO_BLOCK_SAMPLES * 2];
+		end = (int32_t *)&spdif_rx_buffer[AUDIO_BLOCK_SAMPLES * 4];
+	} else {
+		// DMA is receiving to the second half of the buffer
+		// need to remove data from the first half
+		src = (int32_t *)&spdif_rx_buffer[0];
+		end = (int32_t *)&spdif_rx_buffer[AUDIO_BLOCK_SAMPLES*2];
+	}
+
+	left = AudioInputSPDIF3::block_left;
+	right = AudioInputSPDIF3::block_right;
+
+	if (left != NULL && right != NULL) {
+		offset = AudioInputSPDIF3::block_offset;
+		if (offset <= AUDIO_BLOCK_SAMPLES*2) {
+			dest_left = &(left->data[offset]);
+			dest_right = &(right->data[offset]);
+			AudioInputSPDIF3::block_offset = offset + AUDIO_BLOCK_SAMPLES*2;
+
+			do {
+				#if IMXRT_CACHE_ENABLED >=1
+				SCB_CACHE_DCIMVAC = (uintptr_t)src;
+				asm("dsb":::"memory");
+				#endif
+
+				*dest_left++ = (*src++) >> 8;
+				*dest_right++ = (*src++) >> 8;
+
+				*dest_left++ = (*src++) >> 8;
+				*dest_right++ = (*src++) >> 8;
+
+				*dest_left++ = (*src++) >> 8;
+				*dest_right++ = (*src++) >> 8;
+
+				*dest_left++ = (*src++) >> 8;
+				*dest_right++ = (*src++) >> 8;
+
+			} while (src < end);
+		}
+	}
+	else if (left != NULL) {
+		offset = AudioInputSPDIF3::block_offset;
+		if (offset <= AUDIO_BLOCK_SAMPLES*2) {
+			dest_left = &(left->data[offset]);
+			AudioInputSPDIF3::block_offset = offset + AUDIO_BLOCK_SAMPLES*2;
+
+			do {
+				#if IMXRT_CACHE_ENABLED >=1
+				SCB_CACHE_DCIMVAC = (uintptr_t)src;
+				asm("dsb":::"memory");
+				#endif
+
+				*dest_left++ = (*src++) >> 8;
+				src++;
+
+				*dest_left++ = (*src++) >> 8;
+				src++;
+
+				*dest_left++ = (*src++) >> 8;
+				src++;
+
+				*dest_left++ = (*src++) >> 8;
+				src++;
+
+			} while (src < end);
+		}		
+	}
+	else if (right != NULL) {
+		offset = AudioInputSPDIF3::block_offset;
+		if (offset <= AUDIO_BLOCK_SAMPLES*2) {
+			dest_right = &(right->data[offset]);
+			AudioInputSPDIF3::block_offset = offset + AUDIO_BLOCK_SAMPLES*2;
+
+			do {
+				#if IMXRT_CACHE_ENABLED >=1
+				SCB_CACHE_DCIMVAC = (uintptr_t)src;
+				asm("dsb":::"memory");
+				#endif
+
+				src++;
+				*dest_right++ = (*src++) >> 8;
+
+				src++;
+				*dest_right++ = (*src++) >> 8;
+
+				src++;
+				*dest_right++ = (*src++) >> 8;
+
+				src++;
+				*dest_right++ = (*src++) >> 8;
+
+			} while (src < end);
+		}		
+	}
+
+}
+
+
+void AudioInputSPDIF3::update(void)
+{
+	audio_block_t *new_left=NULL, *new_right=NULL, *out_left=NULL, *out_right=NULL;
+
+	// allocate 2 new blocks, but if one fails, allocate neither
+	new_left = allocate();
+	if (new_left != NULL) {
+		new_right = allocate();
+		if (new_right == NULL) {
+			release(new_left);
+			new_left = NULL;
+		}
+	}
+	__disable_irq();
+	if (block_offset >= AUDIO_BLOCK_SAMPLES) {
+		// the DMA filled 2 blocks, so grab them and get the
+		// 2 new blocks to the DMA, as quickly as possible
+		out_left = block_left;
+		block_left = new_left;
+		out_right = block_right;
+		block_right = new_right;
+		block_offset = 0;
+		__enable_irq();
+		// then transmit the DMA's former blocks
+		transmit(out_left, 0);
+		release(out_left);
+		transmit(out_right, 1);
+		release(out_right);
+		//Serial.print(".");
+	} else if (new_left != NULL) {
+		// the DMA didn't fill blocks, but we allocated blocks
+		if (block_left == NULL) {
+			// the DMA doesn't have any blocks to fill, so
+			// give it the ones we just allocated
+			block_left = new_left;
+			block_right = new_right;
+			block_offset = 0;
+			__enable_irq();
+		} else {
+			// the DMA already has blocks, doesn't need these
+			__enable_irq();
+			release(new_left);
+			release(new_right);
+		}
+	} else {
+		// The DMA didn't fill blocks, and we could not allocate
+		// memory... the system is likely starving for memory!
+		// Sadly, there's nothing we can do.
+		__enable_irq();
+	}
+}
+
+bool AudioInputSPDIF3::pllLocked(void)
+{
+	return (SPDIF_SRPC & SPDIF_SRPC_LOCK) == SPDIF_SRPC_LOCK ? true:false;
+}
+
+unsigned int AudioInputSPDIF3::sampleRate(void) {
+	if (!pllLocked()) return 0;
+	return (float)((uint64_t)F_BUS_ACTUAL * SPDIF_SRFM) / (0x8000000ULL * AudioOutputSPDIF3::dpll_Gain()) + 0.5F;
+}
+
+#endif

input_spdif3.h

@@ -0,0 +1,56 @@
+/* Audio Library for Teensy 3.X
+ * Copyright (c) 2019, Paul Stoffregen, paul@pjrc.com
+ *
+ * Development of this audio library was funded by PJRC.COM, LLC by sales of
+ * Teensy and Audio Adaptor boards.  Please support PJRC's efforts to develop
+ * open source software by purchasing Teensy or other PJRC products.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice, development funding notice, and this permission
+ * notice shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+// Frank Bösing
+
+#if defined(__IMXRT1052__) || defined(__IMXRT1062__)
+#ifndef _input_spdif3_h_
+#define _input_spdif3_h_
+
+#include "Arduino.h"
+#include "AudioStream.h"
+#include "DMAChannel.h"
+
+class AudioInputSPDIF3 : public AudioStream
+{
+public:
+	AudioInputSPDIF3(void) : AudioStream(0, NULL) { begin(); }
+	virtual void update(void);
+	void begin(void);
+	static bool pllLocked(void);
+	static unsigned int sampleRate(void);
+protected:
+	//AudioInputSPDIF3(int dummy): AudioStream(0, NULL) {} // to be used only inside AudioInputSPDIF3slave !!
+	static bool update_responsibility;
+	static DMAChannel dma;
+	static void isr(void);
+private:
+	static audio_block_t *block_left;
+	static audio_block_t *block_right;
+	static uint16_t block_offset;
+};
+
+#endif
+#endif

keywords.txt

@@ -10,6 +10,7 @@ AudioInputTDM	KEYWORD2
 AudioInputTDM2	KEYWORD2
 AudioInputPDM	KEYWORD2
 AudioInputUSB	KEYWORD2
+AudioInputSPDIF3	KEYWORD2
 AudioOutputI2S	KEYWORD2
 AudioOutputI2S2	KEYWORD2
 AudioOutputI2SQuad	KEYWORD2
@@ -107,6 +108,7 @@ setHighShelf	KEYWORD2
 muteOutput	KEYWORD2
 unmuteOutput	KEYWORD2
 muteInput	KEYWORD2
+pllLocked	KEYWORD2
 unmuteInput	KEYWORD2
 enableDither	KEYWORD2
 disableDither	KEYWORD2

output_spdif3.cpp

@@ -45,7 +45,19 @@ static int32_t SPDIF_tx_buffer[AUDIO_BLOCK_SAMPLES * 4];
 DMAMEM  __attribute__((aligned(32)))
 audio_block_t AudioOutputSPDIF3::block_silent;
 
-PROGMEM
+#define SPDIF_DPLL_GAIN24 0
+#define SPDIF_DPLL_GAIN16 1
+#define SPDIF_DPLL_GAIN12 2
+#define SPDIF_DPLL_GAIN8 3
+#define SPDIF_DPLL_GAIN6 4
+#define SPDIF_DPLL_GAIN4 5
+#define SPDIF_DPLL_GAIN3 6
+#define SPDIF_DPLL_GAIN1 7
+
+#define SPDIF_DPLL_GAIN SPDIF_DPLL_GAIN8 //Actual Gain
+static const uint8_t spdif_gain[8] = {24, 16, 12, 8, 6, 4, 3, 1};
+
+FLASHMEM
 void AudioOutputSPDIF3::begin(void)
 {
 
@@ -54,86 +66,32 @@ void AudioOutputSPDIF3::begin(void)
 	block_left_1st = nullptr;
 	block_right_1st = nullptr;
 	memset(&block_silent, 0, sizeof(block_silent));
-	uint32_t fs = AUDIO_SAMPLE_RATE_EXACT;
-	// PLL between 27*24 = 648MHz und 54*24=1296MHz
-	// n1, n2 choosen for compatibility with I2S (same PLL frequency) :
-	int n1 = 4; //SAI prescaler 4 => (n1*n2) = multiple of 4
-	int n2 = 1 + (24000000 * 27) / (fs * 256 * n1);
-	double C = ((double)fs * 256 * n1 * n2) / 24000000;
-	int c0 = C;
-	int c2 = 10000;
-	int c1 = C * c2 - (c0 * c2);
-	set_audioClock(c0, c1, c2);
-
-	double pllclock = (c0 + (double)c1 / c2) * 24000000; //677376000 Hz
-
-	//use new pred/podf values
-	n1 = 7; //0: divide by 1 (do not use with high input frequencies), 1:/2, 2: /3, 7:/8
-	n2 = 0; //0: divide by 1, 7: divide by 8
-
-	uint32_t clock = pllclock / (1 + n1) / (1 + n2);
-	uint32_t clkdiv = clock / (fs * 64); // 1 .. 128
-	uint32_t mod = clock % (fs * 64);
-	if (mod > ((fs * 64) / 2)) clkdiv += 1; //nearest divider
-
-	CCM_CCGR5 &= ~CCM_CCGR5_SPDIF(CCM_CCGR_ON); //Clock gate off
-
-	CCM_CDCDR = (CCM_CDCDR & ~(CCM_CDCDR_SPDIF0_CLK_SEL_MASK | CCM_CDCDR_SPDIF0_CLK_PRED_MASK | CCM_CDCDR_SPDIF0_CLK_PODF_MASK))
-		| CCM_CDCDR_SPDIF0_CLK_SEL(0) // 0 PLL4, 1 PLL3 PFD2, 2 PLL5, 3 pll3_sw_clk
-		| CCM_CDCDR_SPDIF0_CLK_PRED(n1)
-		| CCM_CDCDR_SPDIF0_CLK_PODF(n2);
-
-	CCM_CCGR5 |= CCM_CCGR5_SPDIF(CCM_CCGR_ON); //Clock gate on
-
-	if ((SPDIF_SCR & 0x400) != 0) {			//If default value:
-		SPDIF_SCR = SPDIF_SCR_SOFT_RESET;		//Reset SPDIF
-		while (SPDIF_SCR & SPDIF_SCR_SOFT_RESET) {;}	//Wait for Reset (takes 8 cycles)
-		SPDIF_SCR = 0;
-	}
-
-	SPDIF_SCR |=
-		SPDIF_SCR_RXFIFOFULL_SEL(0) |// Full interrupt if at least 1 sample in Rx left and right FIFOs
-		SPDIF_SCR_RXAUTOSYNC |
-		SPDIF_SCR_TXAUTOSYNC |
-		SPDIF_SCR_TXFIFOEMPTY_SEL(3) | // Empty interrupt if at most 4 sample in Tx left and right FIFOs
-		SPDIF_SCR_TXFIFO_CTRL(1) | // 0:Send zeros 1: normal operation
-		SPDIF_SCR_DMA_TX_EN |
-		//SPDIF_SCR_VALCTRL | // Outgoing Validity always clear
-		SPDIF_SCR_TXSEL(5) | //0:off and output 0, 1:Feed-though SPDIFIN, 5:Tx Normal operation
-		SPDIF_SCR_USRC_SEL(3); // No embedded U channel
-		SPDIF_SRCD = 0;
-		SPDIF_STCSCH = 0;
-		SPDIF_STCSCL = 0;
-	
-	SPDIF_SRCD = 0;
-
-	SPDIF_STC = SPDIF_STC_TXCLK_SOURCE(1) //tx_clk input (from SPDIF0_CLK_ROOT)
-		| SPDIF_STC_SYSCLK_DF(0)
-		| SPDIF_STC_TXCLK_DF(clkdiv - 1);
 
+	config_spdif3();
 	const int nbytes_mlno = 2 * 4; // 8 Bytes per minor loop
 
 	dma.TCD->SADDR = SPDIF_tx_buffer;
 	dma.TCD->SOFF = 4;
-	dma.TCD->ATTR = DMA_TCD_ATTR_SSIZE(2) | DMA_TCD_ATTR_DSIZE(2);	
-	dma.TCD->NBYTES_MLNO = DMA_TCD_NBYTES_MLOFFYES_NBYTES(nbytes_mlno) | DMA_TCD_NBYTES_DMLOE | 
+	dma.TCD->ATTR = DMA_TCD_ATTR_SSIZE(2) | DMA_TCD_ATTR_DSIZE(2);
+	dma.TCD->NBYTES_MLNO = DMA_TCD_NBYTES_MLOFFYES_NBYTES(nbytes_mlno) | DMA_TCD_NBYTES_DMLOE |
                          DMA_TCD_NBYTES_MLOFFYES_MLOFF(-8);
 	dma.TCD->SLAST = -sizeof(SPDIF_tx_buffer);
 	dma.TCD->DADDR = &SPDIF_STL;
 	dma.TCD->DOFF = 4;
 	dma.TCD->DLASTSGA = -8;
 	//dma.TCD->ATTR_DST = ((31 - __builtin_clz(8)) << 3);
-	dma.TCD->CITER_ELINKNO = sizeof(SPDIF_tx_buffer) / nbytes_mlno;	
+	dma.TCD->CITER_ELINKNO = sizeof(SPDIF_tx_buffer) / nbytes_mlno;
 	dma.TCD->BITER_ELINKNO = sizeof(SPDIF_tx_buffer) / nbytes_mlno;
 	dma.TCD->CSR = DMA_TCD_CSR_INTHALF | DMA_TCD_CSR_INTMAJOR;
 
 	dma.triggerAtHardwareEvent(DMAMUX_SOURCE_SPDIF_TX);
 
-	update_responsibility = update_setup();	
+	update_responsibility = update_setup();
 	dma.enable();
-	dma.attachInterrupt(isr);	
+	dma.attachInterrupt(isr);
 
 	CORE_PIN14_CONFIG = 3;  //3:SPDIF_OUT
+	SPDIF_SCR |= SPDIF_SCR_DMA_TX_EN;
 	SPDIF_STC |= SPDIF_STC_TX_ALL_CLK_EN;
 //	pinMode(13, OUTPUT);
 }
@@ -167,40 +125,40 @@ void AudioOutputSPDIF3::isr(void)
 
 	src_left = (const int16_t *)(block_left->data);
 	src_right = (const int16_t *)(block_right->data);
-		
+
 	do {
+		#if IMXRT_CACHE_ENABLED >= 2
+		SCB_CACHE_DCCIMVAC = (uintptr_t) dest;
+		asm volatile("dsb");
+		#endif
 		
 		*dest++ = (*src_left++) << 8;
 		*dest++ = (*src_right++) << 8;
 
 		*dest++ = (*src_left++) << 8;
 		*dest++ = (*src_right++) << 8;
-		
+
 		*dest++ = (*src_left++) << 8;
 		*dest++ = (*src_right++) << 8;
 
 		*dest++ = (*src_left++) << 8;
 		*dest++ = (*src_right++) << 8;
-		
-		#if IMXRT_CACHE_ENABLED >= 2
-		SCB_CACHE_DCCIMVAC = (uint32_t) dest - 32;
-		#endif
-		
+
 	} while (dest < end);
-	
+
 	if (block_left != &block_silent) {
-		release(block_left);	
+		release(block_left);
 		block_left_1st = block_left_2nd;
 		block_left_2nd = nullptr;
 	}
 	if (block_right != &block_silent) {
-		release(block_right);	
+		release(block_right);
 		block_right_1st = block_right_2nd;
 		block_right_2nd = nullptr;
 	}
 
 	if (update_responsibility) update_all();
-	//digitalWriteFast(13,!digitalReadFast(13));	
+	//digitalWriteFast(13,!digitalReadFast(13));
 }
 
 void AudioOutputSPDIF3::update(void)
@@ -240,10 +198,10 @@ void AudioOutputSPDIF3::update(void)
 	}
 	__enable_irq();
 	if (block_left) {
-		release(block_left);	
+		release(block_left);
 	}
-	if (block_right) {			
-		release(block_right);		
+	if (block_right) {
+		release(block_right);
 	}
 
 }
@@ -251,8 +209,80 @@ void AudioOutputSPDIF3::update(void)
 void AudioOutputSPDIF3::mute_PCM(const bool mute)
 {
 	if (mute)
-		SPDIF_SCR |= SPDIF_SCR_VALCTRL;		
+		SPDIF_SCR |= SPDIF_SCR_VALCTRL;
 	else
 		SPDIF_SCR &= ~SPDIF_SCR_VALCTRL;
 }
+
+uint32_t AudioOutputSPDIF3::dpll_Gain(void)
+{
+	return spdif_gain[SPDIF_DPLL_GAIN];
+}
+
+PROGMEM
+void AudioOutputSPDIF3::config_spdif3(void)
+{
+	delay(1); //WHY IS THIS NEEDED?
+
+	uint32_t fs = AUDIO_SAMPLE_RATE_EXACT;
+	// PLL between 27*24 = 648MHz und 54*24=1296MHz
+	// n1, n2 choosen for compatibility with I2S (same PLL frequency) :
+	int n1 = 4; //SAI prescaler 4 => (n1*n2) = multiple of 4
+	int n2 = 1 + (24000000 * 27) / (fs * 256 * n1);
+	double C = ((double)fs * 256 * n1 * n2) / 24000000;
+	int c0 = C;
+	int c2 = 10000;
+	int c1 = C * c2 - (c0 * c2);
+	set_audioClock(c0, c1, c2);
+
+	//use new pred/podf values
+	n1 = 7; //0: divide by 1 (do not use with high input frequencies), 1:/2, 2: /3, 7:/8
+	n2 = 0; //0: divide by 1, 7: divide by 8
+
+	CCM_CCGR5 &= ~CCM_CCGR5_SPDIF(CCM_CCGR_ON); //Clock gate off
+
+	CCM_CDCDR = (CCM_CDCDR & ~(CCM_CDCDR_SPDIF0_CLK_SEL_MASK | CCM_CDCDR_SPDIF0_CLK_PRED_MASK | CCM_CDCDR_SPDIF0_CLK_PODF_MASK))
+		| CCM_CDCDR_SPDIF0_CLK_SEL(0) // 0 PLL4, 1 PLL3 PFD2, 2 PLL5, 3 pll3_sw_clk
+		| CCM_CDCDR_SPDIF0_CLK_PRED(n1)
+		| CCM_CDCDR_SPDIF0_CLK_PODF(n2);
+
+	CCM_CCGR5 |= CCM_CCGR5_SPDIF(CCM_CCGR_ON); //Clock gate on
+
+	if (!(SPDIF_SCR & (SPDIF_SCR_DMA_RX_EN | SPDIF_SCR_DMA_TX_EN))) {
+		//Serial.print("Reset SPDIF3");
+		SPDIF_SCR = SPDIF_SCR_SOFT_RESET;		//Reset SPDIF
+		while (SPDIF_SCR & SPDIF_SCR_SOFT_RESET) {;}	//Wait for Reset (takes 8 cycles)
+	} else return;
+
+	SPDIF_SCR =
+		SPDIF_SCR_RXFIFOFULL_SEL(0) |	// Full interrupt if at least 1 sample in Rx left and right FIFOs
+		SPDIF_SCR_RXAUTOSYNC |
+		SPDIF_SCR_TXAUTOSYNC |
+		SPDIF_SCR_TXFIFOEMPTY_SEL(2) |	// Empty interrupt if at most 8 samples in Tx left and right FIFOs
+		SPDIF_SCR_TXFIFO_CTRL(1) |	// 0:Send zeros 1: normal operation
+		SPDIF_SCR_VALCTRL |		// Outgoing Validity always clear
+		SPDIF_SCR_TXSEL(5) |		// 0:off and output 0, 1:Feed-though SPDIFIN, 5:Tx Normal operation
+		SPDIF_SCR_USRC_SEL(3);
+
+	SPDIF_SRPC =
+		SPDIF_SRPC_CLKSRC_SEL(1) |	//if (DPLL Locked) SPDIF_RxClk else tx_clk (SPDIF0_CLK_ROOT)
+		SPDIF_SRPC_GAINSEL(SPDIF_DPLL_GAIN);
+
+	uint32_t pllclock = (c0 + (float)c1 / c2) * 24000000ULL; //677376000 Hz
+	uint32_t clock = pllclock / (1 + n1) / (1 + n2);
+	uint32_t clkdiv = clock / (fs * 64); // 1 .. 128
+	uint32_t mod = clock % (fs * 64);
+	if (mod > ((fs * 64) / 2)) clkdiv += 1; //nearest divider
+
+#if 0
+	Serial.printf("PLL: %d\n",  pllclock);
+	Serial.printf("clock: %d\n", clock);
+	Serial.printf("clkdiv: %d\n", clkdiv);
+#endif
+
+	SPDIF_STC =
+		SPDIF_STC_TXCLK_SOURCE(1) |	//tx_clk input (from SPDIF0_CLK_ROOT)
+		SPDIF_STC_TXCLK_DF(clkdiv - 1);
+}
+
 #endif

output_spdif3.h

@@ -33,16 +33,19 @@ public:
 	AudioOutputSPDIF3(void) : AudioStream(2, inputQueueArray) { begin(); }
 	virtual void update(void);
 	void begin(void);
-	//friend class AudioInputSPDIF;
+	friend class AudioInputSPDIF3;
 	static void mute_PCM(const bool mute);
+	static bool pll_locked(void);
 protected:
 	//AudioOutputSPDIF3(int dummy): AudioStream(2, inputQueueArray) {}
+	static void config_spdif3(void);
 	static audio_block_t *block_left_1st;
 	static audio_block_t *block_right_1st;
 	static bool update_responsibility;
 	static DMAChannel dma;
-	static void isr(void);
+	static void isr(void);	
 private:
+	static uint32_t dpll_Gain() __attribute__ ((const));
 	static audio_block_t *block_left_2nd;
 	static audio_block_t *block_right_2nd;
 	static audio_block_t block_silent;