16bit DMA transfer from EMIFA

David,

Which device are you using?

Do you want to make 32-bit data fit the 16-bit EMIFA bus width (2 transfers each)? Or do you want to just access 16-bit values one-at-a-time?

C6000 devices access memory as byte-addressable. A table of memory addresses would be helpful, showing how you want the values to reside in memory and on the EMIFA device. Also, the nature of the device on the EMIFA bus could help.

Regards,
RandyP

Hi Randy,

Thank you for replying. Our device is a AD7606-4 which after a conversion you can read 4 samples one after the other as 16bit data, so I would say it's one-at-a-time. This 4 samples needs to go in 4 buffers. My setup so far is using StarterWare:

    int16_t Buffers[5000][4];
    EDMA3CCPaRAMEntry paramSet;
    uint8_t *p = (uint8_t *)&paramSet;
    uint32_t i = 0;
    uint32_t tccNum = EDMA3_CHA_GPIO_BNKINT8;
    uint32_t chNum = EDMA3_CHA_GPIO_BNKINT8;

    /* Clean-up the contents of structure variable. */
    for (i = 0; i < sizeof(paramSet); i++)
    {
        p[i] = 0;
    }

    /* Fill the PaRAM Set with Receive specific information. */

    /* srcAddr holds address of SPI Rx FIFO. */
    paramSet.srcAddr = (uint32_t) (SOC_EMIFA_CS4_ADDR);

    /* destAddr is address of memory location named buffer. */
    paramSet.destAddr = (uint32_t) &Buffers[0][0];

    /* aCnt holds the number of bytes in an array. */
    paramSet.aCnt = (uint16_t) sizeof(int16_t);//AD7606 16bit

    /* bCnt holds the number of such arrays to be transferred. */
    paramSet.bCnt = (uint16_t) 4;//adc ch

    /* cCnt holds the number of frames of aCnt*bBcnt bytes to be transferred. */
    paramSet.cCnt = (uint16_t) 5000;

    /* The srcBidx should not be incremented since it is a h/w register. */
    paramSet.srcBIdx = 0;

    /* The destBidx should be incremented for every byte. */
    paramSet.destBIdx = 1;

    /* A sync Transfer Mode. */
    /* srCIdx set to zero since ASYNC Mode is used. */
    paramSet.srcCIdx = 0;

    //difference between the starting addresses of each array ->see Bursting peripherals chapter in Technical Reference Manual, page 555
    paramSet.destCIdx = 5000 * sizeof(int16_t);

    /* Linking transfers in EDMA3 are not used. */
    paramSet.linkAddr = (uint16_t)0xFFFF;
    paramSet.bCntReload = 0;

    paramSet.opt = 0x00000000;

    /* Set TCC field in OPT with the tccNum. */
    paramSet.opt |= ((tccNum << EDMA3CC_OPT_TCC_SHIFT) & EDMA3CC_OPT_TCC);

    /* EDMA3 Interrupt is enabled and Intermediate Interrupt Disabled.*/
    paramSet.opt |= (1 << EDMA3CC_OPT_TCINTEN_SHIFT);

    /* Now write the PaRam Set to EDMA3.*/
    EDMA3SetPaRAM(SOC_EDMA30CC_0_REGS, chNum, &paramSet);

    /* EDMA3 Transfer is Enabled. */
    EDMA3EnableTransfer(SOC_EDMA30CC_0_REGS, chNum, EDMA3_TRIG_MODE_EVENT);

I've setup a GPIO pin as input interrupt whenever the ADC Busy signal has a falling edge.

I'm still learning how to debug the code using EDMA peripheral, hopefully you can have a look and spot anything wrong.

Best regards,

David.

David,

Which device are you using?

From the code, I can tell it has EDMA3. In the Training section of TI.com, there is a training video set for the C6474. In particular, the EDMA3/QDMA/IDMA Module may help you understand some of the features and options available within the EDMA3 module. You can find the complete video set here.

I have not used StarterWare, yet. Is your setup of the EDMA based on StarterWare examples?

When the ADC Busy signal has a falling edge, how much do you want to transfer? Where do you want it to go, buffer arrangement, etc.?

There are more than one register setting (dstBIdx, dstCIdx, bCntReload) that I think may be wrong, but some of these questions will help me understand better. And watching the EDMA3 training video may help you understand some of the registers better. EDMA3 is very similar from one device to another, so I doubt you are using the C6474 but this video may still be useful.

Regards,
RandyP

P.S. - This is the first case I have seen where someone used the SyntaxHighlighter. What do you think of it? Your last four lines are wrapped by the SyntaxHighlighter, too, even though they are after the code segment. Could you tell me, please, if you used the SH for those lines, or if you typed those lines after inserting the SH code, or before inserting the SH code?

Hi Randy,

I forgot to mention, it's the TMS320C6748 device. The setup is based on EDMA StarterWare examples which I successfully used with SPI. 

When ADC Busy has a falling edge, I need to transfer 4 samples, each 16bit. It needs to go in Buffers array, declared as Buffers[5000][4] (of course, I can change the arrangement to suit DMA transfer better). Each of the 4 samples represent a different channel so I would prefer they go into their own array. I'll start watching the videos, thank you for the link.

The syntax highlighter it's very nice to use, it allows separating the code from comments quite nicely. If I remember correctly, I typed the first lines, then started the SyntaxHighlighter, pasted the code, pressed Insert button, back in the editing area pressed Enter to separate the text better, typed in the last comments and pressed Post button, but it appeared as it is now. I tried to go back re-edit the post, but I couln't find a button.

Best regards,

David.

David,

It sounds like you would prefer to declare Buffers[4][5000], which can be done and supported by the EDMA3.

Thank you for the feedback on the SyntaxHighlighter. I will pass your comments on to the forum support team. To edit the post, there is a pencil icon in the bottom left corner of the post, if you are logged in, and this allows you to edit your posts. If it is not there, let me know in your next reply. But please do not edit it right now. I would like the support team to see the effects in your post as they are.

Regards,
RandyP

Hi Randy, 

I had a look at the slides, but still confused about BIDX and CIDX to address buffer positioning. Not to mention, the Error Handler Interrupt is triggered instead of my Dma handler. I was wondering if you could provide an example of how would you setup the EDMA for filling such a buffer, knowing that gpio event triggers availability of 4 samples and sample 0 needs to go in Buffer[0][n], sample 1 into Buffer[1][n], sample 2 into Buffer[2][n], sample 3 into Buffer[3][n] and after n reaches 5000, to receive an interrupt. At the moment I have this:

    int16_t Buffer[4][5000];
    

    EDMA3CCPaRAMEntry paramSet;
    uint8_t *p = (uint8_t *)&paramSet;
    uint32_t i = 0;
    uint32_t tccNum = EDMA3_CHA_GPIO_BNKINT8;
    uint32_t chNum = EDMA3_CHA_GPIO_BNKINT8;

    GPIOBankIntEnable(SOC_GPIO_0_REGS, SYS_INT_GPIO_B8INT);

    /* Clean-up the contents of structure variable. */
    for (i = 0; i < sizeof(paramSet); i++)
    {
        p[i] = 0;
    }

    /* Fill the PaRAM Set with Receive specific information. */

    /* srcAddr holds address of SPI Rx FIFO. */
    paramSet.srcAddr = (uint32_t) (SOC_EMIFA_CS4_ADDR);

    /* destAddr is address of memory location named buffer. */
    paramSet.destAddr = (uint32_t) &Buffer[0][0];

    /* aCnt holds the number of bytes in an array. */
    paramSet.aCnt = (uint16_t) sizeof(int16_t);//T=int16_t for AD7606

    /* bCnt holds the number of such arrays to be transferred. */
    paramSet.bCnt = (uint16_t) 4; //channels

    /* cCnt holds the number of frames of aCnt*bBcnt bytes to be transferred. */
    paramSet.cCnt = (uint16_t) 5000;

    /* The srcBidx should not be incremented since it is a h/w register. */
    paramSet.srcBIdx = 0;

    /* The destBidx should be incremented for every sample. */
    paramSet.destBIdx = 5000 * sizeof(int16_t);	//is it correct?

    /* A sync Transfer Mode. */
    /* srCIdx set to zero since ASYNC Mode is used. */
    paramSet.srcCIdx = 0;

    //difference between the starting addresses of each array ->see Bursting peripherals chapter in Technical Reference Manual, page 555
    paramSet.destCIdx = sizeof(int16_t);///or swap with destbIdx ?

    /* Linking transfers in EDMA3 are not used. */
    paramSet.linkAddr = (uint16_t)0xFFFF;
    paramSet.bCntReload = 0;

    paramSet.opt = 0x00000000;

    /* Set TCC field in OPT with the tccNum. */
    paramSet.opt |= ((tccNum << EDMA3CC_OPT_TCC_SHIFT) & EDMA3CC_OPT_TCC);

    /* EDMA3 Interrupt is enabled and Intermediate Interrupt Disabled.*/
    paramSet.opt |= (1 << EDMA3CC_OPT_TCINTEN_SHIFT);

    //do I need FIFO queue 16bit?
    //paramSet.opt |= (EDMA3CC_OPT_FWID_16BIT << EDMA3CC_OPT_FWID_SHIFT);

    paramSet.opt |= EDMA3CC_OPT_SYNCDIM;	//enable AB sync transfer

    EDMA3SetPaRAM(SOC_EDMA30CC_0_REGS, chNum, &paramSet);

    /* EDMA3 Transfer is Enabled. */
    EDMA3EnableTransfer(SOC_EDMA30CC_0_REGS, chNum, EDMA3_TRIG_MODE_EVENT);

I don't mind if you have it as CSL example.

Best regards,

David.

Hi Randy,

Same as before, pressing few times <Enter> after the code was inserted. The EDMA3CC_OPT_TCC value is actually a bit mask defined in StarterWare to mask the register when setting the TCC channel. The paramSet.opt is initially set to 0x00000000 so the options are added by using OR (|=). I was getting the Interrupt Error Handler because I forgot to call the request channel function, but it works now, I appreciate all your help for understanding EDMA peripheral, the slides were very helpful too and the debugging sequence you suggested. 

Thank you and best regards,

David.

David, Randy,

This might perhaps not be the right forum to ask.

But, I'm about to connect a AD7606 to the TMS320C6748 evaluation board. I intend to use SPI and use AD7606 BUSY signal as an interrupt trigger for the SPI read. I'm curious to know what clock you use to generate the CONVST signal (trigger the AD sampling) in your design, David. I thought I could use a frame clock from the McASP. Is that possible or are there better ways?

Regards,

Henrik

David,

This was very helpful. Thank you very much.

Best regards,

Henrik

 David,

I tried to connect AD7606 to L138LCDK now. Can you share your final SPI and EDMA initialization odf your AD7606 routine files here?

Hi Dmitry1,

I pasted below some of my GPIO initialization code and how I can read a value directly, however I'm not reading via SPI, the ADC is attached to EMIFA interface on CS2 and is triggered by timer and values are transferred via EDMA on busy input falling so I don't think is much help to you.

void ADC7606::Init()

{

g_arGpioOutputs[OUT_ADC_RESET].SetDir(OUTPUT);
g_arGpioOutputs[OUT_ADC_RESET].Write(0);

//Reset();

g_arGpioOutputs[OUT_ADC_RESET].Write(1);

for(uint32_t i = 0; i < 1000; i++)
{
;// reset adc wait here
}
g_arGpioOutputs[OUT_ADC_RESET].Write(0);

g_arGpioOutputs[OUT_ADC_OS0].SetDir(OUTPUT);
g_arGpioOutputs[OUT_ADC_OS0].Write(0);
g_arGpioOutputs[OUT_ADC_OS1].SetDir(OUTPUT);
g_arGpioOutputs[OUT_ADC_OS1].Write(0);
g_arGpioOutputs[OUT_ADC_OS2].SetDir(OUTPUT);
g_arGpioOutputs[OUT_ADC_OS2].Write(0);

g_arGpioInputs[IN_ADC_BUSY].SetDir(INPUT); //prepare busy input when it goes to 0 to read data

// g_arGpioOutputs[OUT_ADC_CONVST].SetDir(OUTPUT);//do NOT use it when TimerConvSt is initialized!
// g_arGpioOutputs[OUT_ADC_CONVST].Write(1); //needs to stay in 1for conv start goes to 0

g_arGpioOutputs[OUT_ADC_OS1].SetDir(OUTPUT);//TODO see TOTUS-102, this line should not be needed

//select filter

filter = 0; //see datasheet

g_arGpioOutputs[OUT_ADC_OS0].Write(filter & 0x01);
g_arGpioOutputs[OUT_ADC_OS1].Write((filter & 0x02) >> 1);
g_arGpioOutputs[OUT_ADC_OS2].Write((filter & 0x04) >> 2);

}

void AD7606::Read()
{
uint32_t timeout = 10;
g_arGpioOutputs[OUT_ADC_CONVST].Write(0); //generate conv start
// for(uint32_t i=0; i < 5; i++)
{
;//do nothing
}
g_arGpioOutputs[OUT_ADC_CONVST].Write(1); //happens at some time later

while(IsBusy() == false && timeout-- > 1)
{
Task_sleep(10);
}
if(timeout <= 1)
{
for(uint8_t i = 0; i < 4; i++)
{
m_iCh[i] = 0;
}
return;
}

timeout = 10;
while(IsBusy() && timeout-- > 1)
{
Task_sleep(10);
}

if(timeout <= 1)
{
for(uint8_t i = 0; i < 4; i++)
{
m_iCh[i] = 0;
}
return;
}

//for(uint8_t i = 0; i < 4; i++)//reading should be faster
{
m_iCh[0] = *AD7606_BASE_ADDR;
m_iCh[1] = *AD7606_BASE_ADDR;
m_iCh[2] = *AD7606_BASE_ADDR;
m_iCh[3] = *AD7606_BASE_ADDR;
}

}

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
bool AD7606::IsBusy()
{
return g_arGpioInputs[IN_ADC_BUSY].Read();
}

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
int16_t AD7606::GetChCounts(uint8_t channel)
{
if(channel >= 4)
{
return 0.0f;
}
return m_iCh[channel];
}

/////////////////////////////////////////////////////////////////////////////////////////////////////////
float32_t AD7606::GetChVoltage(uint8_t channel)
{
if(channel >= 4)
{
return -10.0f; //wrong channel! don't use it in calculations
}
// return 10.0f*(float32_t)m_iCh[channel]/65535.0f; //original
return GetCounts2Voltage(m_iCh[channel]);
}

/////////////////////////////////////////////////////////////////////////////////////////////////////////
float32_t GetCounts2Voltage(int16_t counts)
{
return ((float32_t)counts * 2.5f * 5.0f) / (32768.0f * ADC_VREF);
}

Best regards,

David.

Thank you David. You're very generous.

 David,

sorry for disturb, but can you show what method of GPIO interrupt catching from AD7606 (BUSY signal) your used.

Did you use SYS/BIOS ? maybe you used HWI?

Hi Dmitriy1,

The driver we wrote became quite complicated but I can give you a few hints. The GPIO bank can trigger interrupt but also EDMA event which was set up using LLD EDMA drivers so that EDMA transfers into internal memory the data. My application is running in SYSBIOS and a PSP driver was changed to initialize EDMA and provide pointers to where EDMA should fill the data from ADC. You have to also use linking EDMA events so that it always reloads the next pointer at end of completion in the EDMA interrupt.

Best regards,

David.

 Thank you for response!

I tried to catch GPIO interrupts first. I tried to use HWI for this.

I want to use GP2[15] for receiving interrupt.

My steps:

1) initialization GPIO pins as input

2) initialization GPIO rising-edge interrupt, and enable interrupt globally (I use StarterWare function for this)

/* Sets the pin 48(GP2[15]) as input for receive interrupt from external ADC.*/
    GPIODirModeSet(SOC_GPIO_0_REGS, 48, GPIO_DIR_INPUT);

 /*
    ** Configure falling edge and falling edge triggers on pin 48 to generate
    ** an interrupt
    */
   GPIOIntTypeSet(SOC_GPIO_0_REGS, 48, GPIO_INT_TYPE_FALLEDGE);

 /* Enable interrupts for Bank 2.*/
   GPIOBankIntEnable(SOC_GPIO_0_REGS, 2);

// Initialize DSP interrupt controller
	IntDSPINTCInit();

	// Enable DSP interrupts globally
	IntGlobalEnable();

Next I added HWI in my .cfg file

var hwi0Params = new Hwi.Params();
hwi0Params.instance.name = "hwi0";
hwi0Params.eventId = 49;
hwi0Params.maskSetting = xdc.module("ti.sysbios.interfaces.IHwi").MaskingOption_NONE;
Program.global.hwi0 = Hwi.create(4, "&ad7606_clkpin_toggle", hwi0Params);

But after start I see that programm never enters to ISR("ad7606_clkpin_toggle" function). Should I use something else (task or myidle) for correct use HWI GPIO ?

 Or ypu used onlu services of LLD EDMA for catching GPIO event?

Your code looks ok, don't know the exact event ID association to the bank interrupt. I believe you also need to setup pin interrupt into bank register.

Best regards,

David.