RTOS/TM4C1292NCPDT: uDMA bus error with SPI Interface

Hi Bala,
Since you need to provide the 25MHz MOSC to the PHY is there any reason why you can't use the same MOSC as the clock source for your system clock generation?
Can you not do SysCtlClockFreqSet(SYSCTL_XTAL_25MHZ | SYSCTL_OSC_MAIN | SYSCTL_USE_PLL | SYSCTL_CFG_VCO_480, 120000000);

HI Charles,

i have tried different below combinations and updating the DMA -SPI driver and Ethernet working status below.

DMA-SPI driver works fine only in the below combination where Ethernet is not working.

SysCtlClockFreqSet(SYSCTL_OSC_INT | SYSCTL_USE_PLL | SYSCTL_CFG_VCO_480, 120000000);

SysCtlMOSCConfigSet (SYSCTL_MOSC_PWR_DIS);

 

Rest of the below combination Ethernet is working fine and SPI-DMA driver is not working.

Case 1:

SysCtlClockFreqSet(SYSCTL_XTAL_25MHZ | SYSCTL_OSC_MAIN | SYSCTL_USE_PLL | SYSCTL_CFG_VCO_480, 120000000);

SysCtlMOSCConfigSet (SYSCTL_MOSC_PWR_DIS);

 

Case 2:

SysCtlMOSCConfigSet (SYSCTL_MOSC_PWR_DIS);

Case 3:

SysCtlClockFreqSet(SYSCTL_OSC_INT | SYSCTL_USE_PLL | SYSCTL_CFG_VCO_480, 120000000);

 

Case 4:

SysCtlClockFreqSet(SYSCTL_XTAL_25MHZ | SYSCTL_OSC_MAIN | SYSCTL_USE_PLL | SYSCTL_CFG_VCO_480, 120000000);

Case 5:

if am not adding any of those coding in my program. Running by default configuration of EVM board.

 

This is my main code. where i am using SSI0 for SPI-DMA transfer.

int main(void)

{

/* Eval board initialization functions */
Board_initGeneral();

/* Clock Source Set. This is the place where i have tried different combination*/

SysCtlClockFreqSet(SYSCTL_XTAL_25MHZ | SYSCTL_OSC_MAIN| SYSCTL_USE_PLL |SYSCTL_CFG_VCO_480, 120000000);
SysCtlMOSCConfigSet (SYSCTL_MOSC_PWR_DIS);

Board_initGPIO();
Board_initI2C();
Board_initUART();
Board_initSPI();
UARTUtils_systemInit(0);
Board_initEMAC();

/* LED ON for Indication of BIOS start */
GPIO_write(Board_LED0, Board_LED_ON);

/* Start BIOS */
BIOS_start();

return (0);

}

Am i missing something here?

Regards

Bala

Hi Bala,
Looking at the TivaWare Ethernet examples I see the below clock configuration. Can you do the same and see if you see any difference by adding the SysCtlMOSCConfigSet(SYSCTL_MOSC_HIGHFREQ)?


//
// Make sure the main oscillator is enabled because this is required by
// the PHY. The system must have a 25MHz crystal attached to the OSC
// pins. The SYSCTL_MOSC_HIGHFREQ parameter is used when the crystal
// frequency is 10MHz or higher.
//
SysCtlMOSCConfigSet(SYSCTL_MOSC_HIGHFREQ);

//
// Run from the PLL at 120 MHz.
//
g_ui32SysClock = MAP_SysCtlClockFreqSet((SYSCTL_XTAL_25MHZ |
SYSCTL_OSC_MAIN |
SYSCTL_USE_PLL |
SYSCTL_CFG_VCO_480), 120000000);

Hi Charles,

i have tried setting the clock as you suggested but my DMA-SPI issue is not yet solved.

the below clock setting i have done it in the main code.

g_ui32SysClock = MAP_SysCtlClockFreqSet((SYSCTL_XTAL_25MHZ |
SYSCTL_OSC_MAIN |
SYSCTL_USE_PLL |
SYSCTL_CFG_VCO_480), 120000000);
SysCtlMOSCConfigSet(SYSCTL_MOSC_HIGHFREQ);

what could be the reason for making power down to the external clock is affecting DMA operation which is running on system clock with internal clock frequency? especially the below code
SysCtlMOSCConfigSet (SYSCTL_MOSC_PWR_DIS);


Regards
Bala

Hi Bala,
I don't have an answer. Did you still try to include SysCtlMOSCConfigSet (SYSCTL_MOSC_PWR_DIS) in your code? You should not disable the MOSC if you are using MOSC as the clock source for the PLL.

I don't see anything wrong with the clock setting as you have shown above (with the SysCtlMOSCConfigSet (SYSCTL_MOSC_PWR_DIS removed). You can keep the same clock setting and write a simple DMA-SPI testcase without the ethernet and prove that it should work. If not, we can then investigate what happened.

When you said the DMA-SPI is not working, can you be specific? Do you see any activities on the SPICLK and SIMO and SOMI pins? Check the SSI control/status register and uDMA control/status registers and are they properly set?

Hi Charles,

My DMA-SPI code is alone is working fine with default clock set by EVM board. the problem only with when we enable Board_initEMAC() in my main function.

DMA bus error flag is raised when enabling emac init function.

i didn't setup any of the above mentioned source clock in my SPI DMA code.

i am also setting up my SPI clock source as defined below for DMA -SPI salve operation.

/* Configure the SSI communication parameters. */
SSIConfigSetExpClk(SSI0_BASE, SysCtlClockGet(),
SSI_FRF_MOTO_MODE_0,
SSI_MODE_SLAVE, 4000000, 8);
SSIClockSourceSet(SSI0_BASE, SSI_CLOCK_SYSTEM);

Does this is making any impact on DMA-SPI data transfer while ethernet mac is enabled?

Regards
Bala

Hi Charles,

hereby I am attaching the both SSI0 and uDMA register details while uDMA bus error occurs in SPI-DMA slave mode operation.

 

the following parameters are used for Configure the SysClk.

SysCtlClockFreqSet((SYSCTL_XTAL_25MHZ | SYSCTL_OSC_MAIN | SYSCTL_USE_PLL | SYSCTL_CFG_VCO_480), 120000000);

SysCtlMOSCConfigSet(SYSCTL_MOSC_HIGHFREQ);

 

the return value of SysCtlClockFreqSet() is 120000000. i.e. 120 MHz.

 

the following parameters are used for Configure the SSI0 communication. 

 SSIConfigSetExpClk(SSI0_BASE, 120000000 , SSI_FRF_MOTO_MODE_0,  SSI_MODE_SLAVE, 4000000, 8);

 SSIClockSourceSet(SSI0_BASE, SSI_CLOCK_SYSTEM);

awaiting for the solution ASAP.

Regards

Bala

Hi Bala,
Which TivaWare version are you using?

Hi Charles,

I am using TivaWare_C_Series-2.1.1.71b.

Regards
Bala

Hi Bala,

 Can you try the latest TivaWare version 2.1.4.178. You can download from here . I wonder if you are hitting the SYSCTL#22 errata. 

Hi Charles,

I have tried running with latest TivaWare version 2.1.4.178 and nothing is working-out to solve my issue. the problem still continues as uDMA bus error.

I am getting the same set of register values with latest TivaWare version 2.1.4.178 as I shared earlier.

Regards

Bala

 

Hi Bala,
That is wonderful from your side. Thanks for providing the update. It will be a valuable tip to the forum community. I remembered in a different thread from your colleague I suggested him to try non ping-pong mode to simplify the debug. Anyway, glad that your problem is solved.