CC26xx I2S interface

Oh no!!!  I have committed to using this in the next release...   Which is due to be sent out for prototype runs in about 2 weeks!!

When can I expect that a driver for 26xx will be available (and an example)?     How different are the I2S hardware blocks in the CC3200 and the CC2640?

Help!!!

Thanks...

It's getting near to the end of the year...  Any news on the I2S driver?  

I would really like an example for the CC2640 where the I2S is provides "streaming" data via DMA to a circular buffer in memory.    Is there a way for the CPU to be interrupted when a certain number of samples/transfers have been performed by the DMA (since the last check) (so the contents of the circular buffer can be packetized or moved?

I know exactly what I want to do, but I don't have the visibility into the RTOS/HW/Driver interaction to know how to implement it on CC2640 HW!

Thanks for any insight you can provide.

which pin on the cc2640 to be assigned to the i2s 

Hi,

Like all digital peripheral and GPIOs, the I2S pins can be assigned to any digital IO. You can find the package pin by looking at DIO_0-DIO_30

thanks Torbjorn!

Hi Christin,

Has the mentioned port guide release yet?

../ming

The port guide will be ready in 1 or 2 weeks.

Any update on the I2S driver for CC26xx?

Hi Torbjorn,

Thanks for the reply.  After dealing with other issues, I'm finally back working on the I2S portion of my design.

It sounds like the driver you mentioned will do what I need.   Any chance of getting an early version of it?

I'd hate to spend a lot of time trying to come up with something of my own if there is a TI solution coming out soon.

If it helps, I need to be able to set the rx data to 24 bits and I need to be able to control the sampling frequency.   I only need 1 channel (single phase).

So a partially complete solution may serve my needs.

Thanks!

Hi Mike,

The application examples are still pending release, the RTOS installer comes out first.

The handle to pass to PDMCC26XX_init() is the one defined in the board file. This handle contains the buffer for Object and HWAttr structures. HWAttr should have the IO to use for the microphone signal.

"...
#if defined( CC2650RC_7ID )
/* Initialize PDM driver (invokes I2S) */
PDMCC26XX_init((PDMCC26XX_Handle)&(PDMCC26XX_config));
/* PDM decimation and compression task */
PDM_createTask();
#endif
..."

Then you can start using the driver with Open, then StartStream, and a sequence of RequestBuffer calls. Before calling Open you need to setup the parameters to use, including microphone gain and whether or not to apply compression.

Hi Ed,

I checked the latest RTOS release, and the I2S driver is wrapped inside the PDM driver. Unfortunately it can't be modified just yet, since it's only released as a library for now.

Mike,

Just for sanity (I might have missed if it was mentioned in this in the thread), but can you check if the application has initialized the power module? Do a quick check to see that your application is calling Power_init() before you can open any TI-RTOS driver.

Hi Mike,

Here's how we open and use the driver:

"...

pdmHandle = PDMCC26XX_open(&pdmParams);

if (pdmHandle)
{

 // If you have stuff to prepare before you start the stream then do so. E.g. setup an RF link, or negotiate a serial connection.

 PDMCC26XX_startStream(pdmHandle);

...

// Then upon callback, with data ready, we can request buffer. Preferably do this from application task context, instead of in the callback. We typically just post a semaphore in the callback function

void yourTaskFx()
{
 PDMCC26XX_BufferRequest bufferRequest;
 PDMCC26XX_BufferRelease bufferRelease;

 if (PDMCC26XX_requestBuffer(pdmHandle, &bufferRequest)) {
 // Use the data

 // Release after use
 bufferRelease.bufferHandle = bufferRequest.bufferHandle;
 PDMCC26XX_releaseBuffer(pdmHandle, &bufferRelease);
}

..."

Thanks again for the quick reply, Torbjorn. 

It seems I may have a different version of TI RTOS or the PDM driver. The PDMCC26XX_BufferRelease does not exist in my version. I grepped the whole tree for it. I did see a PDMCC26CC_I2S_BufferRelease, however it is not compatible. 

In addition, the call to PDMCC26XX_open() is still failing. I copied your example params and had the exact same issue. PDMCC26XX_open() is not returning. 

My top level folder is 

tirtos_cc13xx_cc26xx_2_15_00_17

and the tidrivers folder is

tidrivers_cc13xx_cc26xx_2_15_00_26

Does that look right? 

Thanks again for your help on this. I can tell you that a lot of people on the e2e zigbee/6lowpan forum have been waiting for this. 

Hi Mike,

You've got the latest version of RTOS. There is a sample implementation in the works which would really answer your question, but it's going to come out around feb/march.

I'll try to give you the pieces here. This will only show you how to open the driver and start the stream. It will either run to completion, or run into an error likely because of allocation issues. You should call stopStream and close when you're done with it. Also notice that this one assumes that you have access to the UART driver. You can either look past these steps or look at the UART example. If you run without compression you'll have to set the baudrate to > 256000 --> 460800. This is because 16kHz 16-bit audio produces a 256kbps stream uncompressed. Compression produces a fourth of that.

In board file:

#include <ti/drivers/pdm/PDMCC26XX.h>
PDMCC26XX_Object pdmCC26XXObject = {0};

const PDMCC26XX_HWAttrs pdmCC26XXHWAttrs = {
.micPower = Board_MIC_POWER,
.taskPriority = 2,
};

/* PDM configuration structure */
const PDMCC26XX_Config PDMCC26XX_config[] = {
{
.object = &pdmCC26XXObject,
.hwAttrs = &pdmCC26XXHWAttrs
},
{NULL, NULL}
};

In main():
/* Initialize PDM driver (invokes I2S) */
PDMCC26XX_init((PDMCC26XX_Handle)&(PDMCC26XX_config));

In your application:

PDMCC26XX_Params pdmParams = {

.callbackFxn = RSA_PDMCC26XX_callbackFxn,
.useDefaultFilter = true,
.decimationFilter = NULL,
.micGain = PDMCC26XX_GAIN_12,
.micPowerActiveHigh = true,
.applyCompression = true,
.startupDelayWithClockInSamples = 256,
.retBufSizeInBytes = AUDIO_BUF_COMPRESSED_SIZE+PCM_METADATA_SIZE,
.mallocFxn = (PDMCC26XX_MallocFxn) malloc, // Should point to an allocation function of your choice, e.g. RTOS default
.freeFxn = (PDMCC26XX_FreeFxn) free, // Should point to a de-allocation function of your choice, e.g. RTOS default
.custom = NULL

};

/* Open PDM driver */

pdmHandle = PDMCC26XX_open(&pdmParams);

if(pdmHandle)
{

/* Stream immediately if we simply dump over UART. */
PDMCC26XX_startStream(pdmHandle);

}

static void RSA_PDMCC26XX_callbackFxn(
PDMCC26XX_Handle handle,
PDMCC26XX_StreamNotification *pStreamNotification)
{

if(pStreamNotification->status == PDMCC26XX_STREAM_BLOCK_READY)
{

events |= RSA_PCM_BLOCK_READY;

}

Semaphore_post(rsaSem);

}

void yourTaskFx()
{

if(events & RSA_PCM_BLOCK_READY)
{

while(PDMCC26XX_requestBuffer(pdmHandle, &bufferRequest))
{

if(bufferRequest.status == PDMCC26XX_STREAM_BLOCK_READY)
{

static int waitCnt = 0;

if(waitCnt++ > 3)
{

if(pdmParams.applyCompression)
{

UART_write(uart, (Char const *)bufferRequest.buffer,
PCM_METADATA_SIZE + AUDIO_BUF_COMPRESSED_SIZE;

}

else
{

UART_write(uart, (Char const *)bufferRequest.buffer +
PCM_METADATA_SIZE, AUDIO_BUF_UNCOMPRESSED_SIZE);

}

}

}

}
events &= ~RSA_PCM_BLOCK_READY;

}

free(bufferRequest.buffer,0);

}

Hi Torbjorn,

Like others, my application is to take the mem mic data and transmit to another side which could be a mobile or another CC2640 device. I have the following questions with the current (and future) implementation of the PDM driver:

1. Can the driver support other sample rates and pcm data width, like 8K samples x 16 bits? Please specify the case for the current driver and the driver in the future.
2. What kind of compression applies to the PCM data when compression is set on? We would need to know how to decode the pcm data at the other end.
3. "AUDIO_BUF_COMPRESSED_SIZE" was not defined in either PDMCCXX.h or PDMCCXX_utils.h. What would be the value of this define in this case?
4. Would this driver be open with source code in the future or will it be stay close?
5. You quote: "There is a sample implementation in the works which would really answer your question, but it's going to come out around feb/march." Is this sample application the same as the "port guide" that mentioned by Christian in this same thread?

thanks a lot in advance.

../ming

Hi Torbjorn,

Can the PDM driver be used with the older version of TI-RTOS (I"m currently using tirtos_simplelink_2_13_00_06).   I believe this was suggested by Cristin?

If so, are there any steps beyond the obvious ones of copying in PDMCC26XX.h, PDMCC26XX_util.h?   Are there other files required?

If not, when will the porting guide be available?

Thanks!

Hi Ed,

There is more information in the register description.

1. 
   A: Number of words to sample before DMA switches to next pointer
   B: Yes
   C: Internally managed and used variable
   D: DMA will transfer from all channels into the same buffer. If you have two or more channels then the size is different between DMA and channel
2. Yes
3. It is required to kick of sampling, but nothing more. It is used to have highly synchronized audio networks. It was designed for the PurePathWireless protocol.

Once the stream is started all you'll have to deal with is giving the module a new pointer every time it finishes a transfer.

Thanks again Torbjorn. Unfortunately, I am still stuck.

First, I switched from the empty_min project to the empty project, to ensure no related kernel functions were being disabled for the minimal footprint. 
Then I re-introduced pieces of the code, and as soon as I try to try to open the pdmHandle, the program loses it. The open function is not returning. 

I am calling PDMCC26XX_open() after PDMCC26XX_init() during the main() setup, before calling bios_start(). 
My params are copied from yours, with the exception of retBufSizeInBytes. 
I do not have these macros defined: AUDIO_BUF_COMPRESSED_SIZE, PCM_METADATA_SIZE
I've tried to call open() with various hardcoded buf sizes from 16 to 1024 bytes, all with the same result. 

I am using IAR for ARM v7.40.3.8938. 

I had some build errors when I tried to make my board file PDM section look like yours.
The PDM_I2S_Object was not defined without adding some of the code below - pdmC26XXI2SHWAttrs & PDMCC26XX_I2S_config

The PDM section of my board file looks like this (default from the new examples that came with the TI-RTOS):

/*
* ============================= PDM begin ====================================
*/
/* Place into subsections to allow the TI linker to remove items properly */
#if defined(__TI_COMPILER_VERSION__)
#pragma DATA_SECTION(PDMCC26XX_config, ".const:PDMCC26XX_config")
#pragma DATA_SECTION(pdmCC26XXHWAttrs, ".const:pdmCC26XXHWAttrs")
#pragma DATA_SECTION(PDMCC26XX_I2S_config, ".const:PDMCC26XX_I2S_config")
#endif

/* Include drivers */
#include <ti/drivers/pdm/PDMCC26XX.h>
#include <ti/drivers/pdm/PDMCC26XX_util.h>

/* PDM objects, one for PDM driver, one for PDM/I2S helper file */
PDMCC26XX_Object pdmCC26XXObjects[CC2650STK_PDMCOUNT];
PDMCC26XX_I2S_Object pdmCC26XXI2SObjects[CC2650STK_PDMCOUNT];

/* PDM driver hardware attributes */
const PDMCC26XX_HWAttrs pdmCC26XXHWAttrs[CC2650STK_PDMCOUNT] = {
{
.micPower = Board_MIC_POWER,
.taskPriority = 1
}
};

/* PDM configuration structure */
const PDMCC26XX_Config PDMCC26XX_config[] = {
{
.object = &pdmCC26XXObjects[0],
.hwAttrs = &pdmCC26XXHWAttrs[0]
}
};

/* PDM_I2S hardware attributes */
const PDMCC26XX_I2S_HWAttrs pdmC26XXI2SHWAttrs[CC2650STK_PDMCOUNT] = {
{
.baseAddr = I2S0_BASE,
.intNum = INT_I2S_IRQ,
.powerMngrId = PowerCC26XX_PERIPH_I2S,
.intPriority = ~0,
.mclkPin = PIN_UNASSIGNED,
.bclkPin = Board_AUDIO_CLK,
.wclkPin = PIN_UNASSIGNED,
.ad0Pin = Board_AUDIO_DI,
}
};

/* PDM_I2S configuration structure */
const PDMCC26XX_I2S_Config PDMCC26XX_I2S_config[] = {
{
.object = &pdmCC26XXI2SObjects[0],
.hwAttrs = &pdmC26XXI2SHWAttrs[0]
},
{NULL, NULL}
};

I am doing the same thing but got stuck in a different way. I am running BTStack 2.1, and I am back porting the PDM driver from tirtos_cc13xx_cc26xx_2_15_00_17 to tirtos_simplelink_2_13_00_06.

I got those linker errors as below. How do I bring the PDM library files (pdm_cc26xxware.aem3, pdm_cc26xxware.am3g, pdm_cc26xxware.arm3) into the project? I tried to add the lib files into the workspace, but it doesn't work. 

<Linking>

 undefined               first referenced
  symbol                     in file     
 ---------               ----------------
 PDMCC26XX_init          <whole-program> 
 PDMCC26XX_open          <whole-program> 
 PDMCC26XX_requestBuffer <whole-program> 
 PDMCC26XX_startStream   <whole-program> 

Please help. Thanks.

../ming

I got the method to include the PDM library from this link, and I can include the PDM library.

Now, I got the following linker error:

<Linking>

 undefined               first referenced                                                                                  
  symbol                     in file                                                                                       
 ---------               ----------------                                                                                  
 Power_releaseDependency C:\ti\tirtos_simplelink_2_13_00_06\packages\ti\drivers\pdm\lib\pdm_cc26xxware.aem3<PDMCC26XX.oem3>
 Power_setConstraint     C:\ti\tirtos_simplelink_2_13_00_06\packages\ti\drivers\pdm\lib\pdm_cc26xxware.aem3<PDMCC26XX.oem3>

>> Compilation failure
 Power_setDependency     C:\ti\tirtos_simplelink_2_13_00_06\packages\ti\drivers\pdm\lib\pdm_cc26xxware.aem3<PDMCC26XX.oem3>

error #10234-D: unresolved symbols remain
error #10010: errors encountered during linking; "Ble.out" not built
gmake: *** [Ble.out] Error 1
gmake: Target `all' not remade because of errors.

**** Build Finished ****

I don't understand why these 3 standard Power_XXX APIs will not be found. Is that related to different TIRTOS version?

Please help

Thanks Torbjorn,

I'm still struggling with how the DMA and Channel buffers are expected to be laid out if one wants to use the CC26xx I2S library and the control table structure.

I got the I2S pins to "wiggle" using the example code that Andrei posted (Thanks Andrei!!!), but this code hits HW registers directly and I am hoping to use the CC26xx calls.

It appears, by looking at the code in i2s.c,  that the I2SPointerUpdate() call has some expectation of the buffer/channel memory configuration.

Can you describe what it expects?    Is the DMA buffer a large area of memory that is some integer multiple of the size of a channel buffer?

I understand that the I2S DMA unit "chains" the buffers using the NXTPTR, so one could set up a set of buffers and cycle through them.   It doesn't look like this is what the I2SPointerUpdate() code is doing, but rather is cycling through a large memory area.

I haven't seen any documentation on this except the online doxygen generated pages (and they don't really describe what is expected).

TI needs to understand that the documentation should describe the functionality so that someone outside TI (ie. those of us who don't have access to internal documents)  can actually use the HW...

Thanks...

Hi Ed. 

As a sanity check,  you could register the ISR using the lower level Hwi functions.  
That way you could at least see if your I2S pins wiggle, and maybe pinpoint the problem to the I2SIntRegister() API. 

i.e. - 

Hwi_Params hwiParams;

// Setup HWI handler
Hwi_Params_init(&hwiParams);
Hwi_construct(&hwiStruct, INT_I2S, i2s_Isr, &hwiParams, NULL);

Hi Mike,

Hitting the registers directly seems to work for the interrupt.   The I2SIntRegister function causes the app to crash (evidently does an illegal access and traps to a holding loop).

Thanks again to Andrei for posting his solution that hits registers directly.

After lots of "trial-and-error" I found a sequence of CC26xx library calls that seem to work for I2S.

It seems that the library is incomplete though.  There are a few places where direct hardware register accesses seem to be required (at least I couldn't find any CC26xx calls to do the equivalent functionality).    

I also found that the order of initialization has to be different than prescribed in the reference manual.   I found this by reading through the i2s.h and i2s.c code, noticing that it expected certain items from the control table to be initialized.    Performing the sequence in the prescribed order caused uninitialized values to be used.

Also, I expected the I2SPointerUpdate to perform buffer address calculations and properly set the PTRNEXT register.   It didn't work the way I expected, so I used the I2SPointerSet function to do the buffer update "manually".

This code seems to work for me, but I'd appreciate any updates, or an explanation of what TI had in mind for their buffering scheme if I'm doing something wrong.

Here is the code:

#define NUM_MIC_SAMPLES_PACKET    48

#define NUM_MIC_BUF 6

uint8_t micBuffer[NUM_MIC_SAMPLES_PACKET*3*NUM_MIC_BUF];

I2SControlTable g_controlTable;          // Define global table space

uint32_t intStatus = 0;

uint8_t index_in = 0;
uint8_t justReadIndex;

static PIN_State pinState;
static PIN_Handle pinHandle;
static ti_sysbios_family_arm_m3_Hwi_Struct hwiStruct;

static void mic_i2sEnable(bool en) {
  if(en == true) {
    I2SIntEnable(I2S0_BASE, I2S_INT_DMA_IN | I2S_INT_TIMEOUT | I2S_INT_BUS_ERR | I2S_INT_WCLK_ERR | I2S_INT_PTR_ERR);
    I2SEnable(I2S0_BASE);
  } else {
    I2SDisable(I2S0_BASE);
  }
}

/*
* Interrupt service routine.
*
*/
static void mic_i2sISR(void) {

  intStatus = I2SIntStatus(I2S0_BASE, true);
  I2SIntClear(I2S0_BASE, I2S_INT_DMA_IN);

  justReadIndex = index_in;

  uint8_t* newPtr = &(micBuffer[NUM_MIC_SAMPLES_PACKET * 3 * index_in]);
  index_in++; if(index_in == NUM_MIC_BUF) index_in = 0;
  I2SPointerSet(I2S0_BASE,true,newPtr);
  //I2SPointerUpdate(I2S0_BASE,true);      // Update the input pointer - why doesn't this work??

  i2s_extractData();    // Most of work done in task;  justReadIndex points to just received buffer

    // Wake the task
  micRdy = true;
  Semaphore_post(localSem);
}

static void mic_i2sConfigureIntrCallback(void (*pfnHandler)(void)) {

//#if 0
  Hwi_Params hwiParams;

    // Setup HWI handler - This works... 
  Hwi_Params_init(&hwiParams);
  Hwi_construct(&hwiStruct, INT_I2S,pfnHandler, &hwiParams, NULL);
//#endif

#if 0

     // This doesn't work

  I2SIntRegister(I2S0_BASE, pfnHandler);

#endif
}

static void mic_i2sEnableBclk(bool en) {
  if(en == true) {
    PRCMAudioClockEnable(); // Turn on BCLK
  } else {
    PRCMAudioClockDisable(); // Turn off BCLK
  }
PRCMLoadSet();
}

static void mic_i2sPinConfig() {
      // Assign physical pins for I2S operation
  PIN_Status res = PIN_SUCCESS;
  PIN_Config pinTable[] = {
    Board_I2S0_BCLK | PIN_INPUT_DIS | PIN_PUSHPULL | PIN_GPIO_OUTPUT_EN | PIN_GPIO_HIGH,         // BCLK
    Board_I2S0_WCLK | PIN_INPUT_DIS | PIN_PUSHPULL | PIN_GPIO_OUTPUT_EN | PIN_GPIO_LOW,         // WCLK
    Board_I2S0_SD | PIN_INPUT_EN | PIN_PULLUP,                                                                                                       // SD
    Board_I2S0_CHIP_EN | PIN_INPUT_DIS | PIN_PUSHPULL | PIN_GPIO_OUTPUT_EN | PIN_GPIO_LOW,   // Enable (use for debug)
    PIN_TERMINATE
  };
     // Open and assign pins through pin driver
  pinHandle = PIN_open(&pinState, pinTable);
    // Check to make sure pins are not already allocated
  if(NULL == pinHandle) while(1); // Stall here on error!

    // Set IO muxing for the I2S pins
  res |= PINCC26XX_setMux(pinHandle, Board_I2S0_WCLK, IOC_PORT_MCU_I2S_WCLK);
  res |= PINCC26XX_setMux(pinHandle, Board_I2S0_BCLK, IOC_PORT_MCU_I2S_BCLK);
  res |= PINCC26XX_setMux(pinHandle, Board_I2S0_SD, IOC_PORT_MCU_I2S_AD0);

  if(PIN_SUCCESS != res) while(1); // Stall here on error!
}

static void mic_i2sClockConfig() { // Set up I2S clocks

  Power_setConstraint(Power_SB_DISALLOW);
  if(!Power_setDependency(PERIPH_I2S)) while(1); // Stall here on error!

  PRCMPeripheralRunEnable(PRCM_PERIPH_I2S);                    // I2S Clock Gate for Run Mode
  PRCMPeripheralSleepDisable(PRCM_PERIPH_I2S);                // I2S Clock Gate for Sleep Mode
  PRCMPeripheralDeepSleepDisable(PRCM_PERIPH_I2S);      // I2S Clock Gate for DeepSleep Mode

       // No PRCMPeripheral Library call for this????
                                                            // I2S Clock Control. (Use internally generated clock)
  HWREG(PRCM_BASE + PRCM_O_I2SBCLKSEL) = PRCM_I2SBCLKSEL_SRC;

                                                           // Use this to set up custom sample rate
  PRCMAudioClockConfigSetOverride(PRCM_WCLK_DUAL_PHASE | PRCM_WCLK_POS_EDGE,
                                                                     0, // MstDiv
                                                                240, // BitDiv 16KHz:60 8KHz:120 6.4KHz:150 6.0KHz:160 4KHz:240 2KHz:480
                                                                   25 // WordDiv
  );

  PRCMLoadSet(); // Load clock values into clock unit
}

static void mic_i2sPeriphConfig() {
                                                                         // Inform I2S where to get its clock
  I2SClockConfigure(I2S0_BASE, I2S_INT_WCLK | I2S_INVERT_WCLK);

  I2SAudioFormatConfigure(I2S0_BASE,                                // I2S registers
                                                   I2S_MEM_LENGTH_24          // 24-bits packed in mem
                                                 | I2S_POS_EDGE                       // Sampled on pos edge
                                                 | I2S_DUAL_PHASE_FMT       // 2 phases in I2S
                                                 | I2S_WORD_LENGTH_24,     // 24-bit samples
                                                  1 // 1 bit delay
  );

  I2SChannelConfigure(I2S0_BASE,                                       // I2S registers
                                           I2S_LINE_INPUT                             // Chan 0: I2S - Mono
                                         | I2S_MONO_MODE,
                                           I2S_LINE_UNUSED,                      // Chan 1: unused
                                           I2S_LINE_UNUSED                       // Chan 2: unused
  );
}

static void mic_i2sMemoryConfig() {

  I2SBufferConfig(I2S0_BASE,                                          // I2S base
                              (uint32_t) micBuffer,                             // Address of Input Buffer
                              0,                                                             // Address of Output Buffer - not used
                              NUM_MIC_SAMPLES_PACKET,     // Number of samples per buffer
                              NUM_MIC_SAMPLES_PACKET      // Number of samples per channel
  );
  I2SPointerUpdate(I2S0_BASE,
                                    true                                                   // Update input pointer
  );
}

static void mic_i2sSampleStampConfig() {

                                        // Set up SampleStamp for Input,
                                        // but not output
                                        // WCLK Counter Period Value

                                        // No library call for this
  HWREG(I2S0_BASE + I2S_O_STMPWPER) = NUM_MIC_SAMPLES_PACKET;

  I2SSampleStampConfigure(I2S0_BASE, true, false);

  I2SSampleStampEnable(I2S0_BASE);      // Start SampleStamp
}

static void micStart() {

  mic_i2sEnable(true);                                     // Enable I2S; pointer copied
  I2SPointerUpdate(I2S0_BASE,true);         // Update the input pointer
}

static void micStop() {
}

static inline void i2s_extractData(void) {

}

/*********************************************************************
* @fn StethPatchMic_reset
*
* @brief Reset
*
* @param none
*
* @return none
*/
void StethPatchMic_reset() {

  // Performed once
  // Sets up microphone
  g_pControlTable = &g_controlTable; // Assign pointer

  mic_i2sPinConfig();                         // Step 1. Assign Pins
  mic_i2sEnableBclk(false);             // Make sure BCLK is off
  mic_i2sClockConfig();                    // Step 2. Configure the clocks
  mic_i2sPeriphConfig();                  // Step 3. Configure the I2S
  mic_i2sEnableBclk(true);              // Step 4. Enable BCLK
  mic_i2sMemoryConfig();                      // Do memory config here instead of below
  mic_i2sSampleStampConfig();                        // Step 5. Configure SampleStamp Gen
  mic_i2sConfigureIntrCallback(mic_i2sISR); // Step 7.
  // mic_i2sMemoryConfig();

}