C674x Edma configuration

Veronica Getaz

Hello,

I am having some troubles configuring the EDMA for a bcnt > 1.

I use the rCSL_quick_start EDMA_event_trig_dspL138 example code, the modified code is in attachment.

I succeed to transfer with the EDMA from the external memory ( using the EMIF) to the internal memory.The edma transfers are a-synchronized with the timer. This successful EDMA configuration is: ACNT = 3, BCNT = 1, CCNT = 1

But, when I change only the bcnt value, leaving a a-synchronized transfer (ACNT = 3, BCNT = 2, CCNT = 1), I can actually see the multiple transfers happenning, synchronized with the timer, but the EDMA transfer completion ISR is now never reached.

Any help will be highly appreciated.

Veronica

Fullscreen 7446.main.c Download

/*-----------------------------------------------------------------------------
 * Project: EDMA_event_trig_dspL138
 * File: main.c
 *
 * This file contains the test / demo code to demonstrate basic EDMA 
 * operations using the Regsiter CSL macros.
 *
 * Copyright (C) 2010 Texas Instruments Incorporated - http://www.ti.com/
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *    Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 *    Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the
 *    distribution.
 *
 *    Neither the name of Texas Instruments Incorporated nor the names of
 *    its contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * 
 *-----------------------------------------------------------------------------
 * 
 * EDMA_event_trig_dspL138
 * -----------------------
 * 	Purpose: Demonstrate usage of EDMA rCSL
 * 
 *	Example Description:
 * 		This example initializes the EDMA3 channel controller using the rCSL
 * 		macros to perform a simple 1kB internal memory to memory transfer upon
 * 		a timer time-out event. Once initialized, the timer is enabled once to
 * 		trigger the EDMA3 event. The EDMA3 channel controller consequently
 * 		sends a transfer request to the transfer controller and the data in
 * 		the source buffer is transferred to the destination buffer. Upon
 * 		completion of the transfer, the EDMA3 channel controller sends an
 * 		interrupt to the CPU and the source and destination buffers are
 * 		compared to verify the EDMA3 transfer. The results are printed to
 * 		the console.
 *
 *	-> SEE README IN PROJECT FOLDER FOR DETAILS AND STEPS TO RUN EXAMPLE <-
 *
 *---------------------------------------------------------------------------*/
#include <EDMA_event_trig_dspL138.h>

#include <ti/pspiom/cslr/cslr_emifa2.h>

//Uint8 srcBuffer[SRC_ARRAYS][SRC_ARRAY_SIZE];
Uint8 *srcBufferP = (Uint8 *)CSL_EMIFA_CS2_ADDR;
//Uint8 dstBuffer[DST_ARRAYS][DST_ARRAY_SIZE];
Uint8 dstBuffer[DST_ARRAYS*DST_ARRAY_SIZE];
Uint8 *dstBufferP = &dstBuffer[0];
Uint8 *dataPointer;


//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
CSL_EmifaRegsOvly emifaRegs = (CSL_EmifaRegsOvly)(CSL_EMIFA_0_REGS);

#define A_CNT 		3
#define B_CNT 		1
#define C_CNT 		1
//#define B_CNTRLD	B_CNT
#define B_CNTRLD	0

#define SB_IDX		0
#define SC_IDX		0
#define DB_IDX		A_CNT
#define DC_IDX		A_CNT // A-sync
//#define DC_IDX		(A_CNT*B_CNT) // AB-sync

volatile int runTimerCount=0;
volatile int runExampleCount = 0;

//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------


/*-----------------------------------------------------------------------------
 *
 * 				BEGIN EXAMPLE: EDMA_event_trig_dspL138
 *
 *---------------------------------------------------------------------------*/
void main (void)
{
	// Initialize OMAPL138 EVM (Timer w/DSP)
	init_OMAPL138();
	
	// Enable Peripherals (EDMACC, EDMATC0)
	enable_module_clocks();
	
	// Setup Peripherals; Run Example
	if(modulesEnabled)
	{
		// Configure the 64 Bit Timer0 as 32 Bit Unchain
		setup_Timer0();
		
		// Setup EMIFA
		setup_EMIFA();

		// Setup EDMA for Event 10 Transfer
		setup_EDMA();
		
		// Map System Interrupts to the DSP Interrupt Controller
		setup_DSP_INTC();
		
		// Run Example
		EDMA_event_trig_DSPexample();
	}
}/* End of main */


/*-----------------------------------------------------------------------------
 *
 * 						Internal Functions Defined
 * 
 *---------------------------------------------------------------------------*/
static void init_OMAPL138 (void)
{
	// Open Permissions to SYSCFG Registers
	CSL_FINS(sysRegs->KICK0R, SYSCFG_KICK0R_KICK0, KICK0_KEY);
	CSL_FINS(sysRegs->KICK1R, SYSCFG_KICK1R_KICK1, KICK1_KEY);
	
	// Configure Timer0 with the DSP CPU
	CSL_FINST(sysRegs->SUSPSRC, SYSCFG_SUSPSRC_TIMER64P_0SRC, DSP);
	
	// Close Permissions to SYSCFG Registers
	CSL_FINS(sysRegs->KICK0R, SYSCFG_KICK0R_KICK0, KICK_LOCK);
}/* init_OMAPL138 */

/*---------------------------------------------------------------------------*/

static void enable_module_clocks (void)
{
	modulesEnabled = FALSE;
	
	// Ensure previous initiated transitions have finished 
	if(check_psc_transition(CSL_PSC_0) == pscTimeout)
		return;
	
	// Enable peripherals; Initiate transition
	CSL_FINST(psc0Regs->MDCTL[CSL_PSC_CC0], PSC_MDCTL_NEXT, ENABLE);
	CSL_FINST(psc0Regs->MDCTL[CSL_PSC_TC0], PSC_MDCTL_NEXT, ENABLE);
	CSL_FINST(psc0Regs->MDCTL[CSL_PSC_EMIFA], PSC_MDCTL_NEXT, ENABLE);
	CSL_FINST(psc0Regs->PTCMD, PSC_PTCMD_GO0, SET);
	
	// Ensure previous initiated transitions have finished
	if(check_psc_transition(CSL_PSC_0) == pscTimeout)
		return;
	
	// Ensure EDMA3CC enabled
	if(check_psc_MDSTAT(CSL_PSC_0, CSL_PSC_CC0, CSL_PSC_MDSTAT_STATE_ENABLE)
			== pscTimeout)
		return;
	
	// Ensure EDMA3TC0 enabled
	if(check_psc_MDSTAT(CSL_PSC_0, CSL_PSC_TC0, CSL_PSC_MDSTAT_STATE_ENABLE)
			== pscTimeout)
		return;
	
	// Ensure CSL_PSC_EMIFA enabled
	if(check_psc_MDSTAT(CSL_PSC_0, CSL_PSC_EMIFA, CSL_PSC_MDSTAT_STATE_ENABLE)
			== pscTimeout)
		return;


	modulesEnabled = TRUE;
}/* enable_module_clocks */

/*---------------------------------------------------------------------------*/

static void setup_Timer0 (void)
{
	// Set Timer0 as 32 Bit Unchain
	CSL_FINST(tmr0Regs->TGCR, TMR_TGCR_TIMMODE, 32BIT_UNCHAIN);
	
	// Remove Timer0:12 from Reset
	CSL_FINST(tmr0Regs->TGCR, TMR_TGCR_TIM12RS, NO_RESET);
	
	// Set Timer0:12 Period; 1 Second
	//CSL_FINS(tmr0Regs->PRD12, TMR_PRD12_PRD12, CSL_ASYNC_2_FREQ);
	CSL_FINS(tmr0Regs->PRD12, TMR_PRD12_PRD12, 24u); //24000000u
	
	// Select Internal Clock for Timer0:12 (24 MHz)
	CSL_FINST(tmr0Regs->TCR, TMR_TCR_CLKSRC12, INTERNAL);
	
	// Reset the Counter for Timer0:12
	CSL_FINST(tmr0Regs->TIM12, TMR_TIM12_TIM12, RESETVAL);
	
	// Disable the New Timer Features
	CSL_FINST(tmr0Regs->TGCR, TMR_TGCR_PLUSEN, DISABLE);
}/* setup_Timer0 */

/*---------------------------------------------------------------------------*/

static void setup_EMIFA (void)
{
	volatile Uint32 thisVal;

	// Configure EMIFA Signals
	CSL_FINST(sysRegs->PINMUX7, SYSCFG_PINMUX7_PINMUX7_3_0, NEMA_CS2);
	thisVal = sysRegs->PINMUX8;
	sysRegs->PINMUX8 = 0x11111111 ;
	thisVal = sysRegs->PINMUX8;
	thisVal = sysRegs->PINMUX9;
	sysRegs->PINMUX9 = 0x11111111 ;
	thisVal = sysRegs->PINMUX9;

	// Disable the interrupts CSL_EMIFA_INTMSKCLR_WR_MASK_CLR_MASK
	CSL_FINST(emifaRegs->INTMSKCLR, EMIFA_INTMSKCLR_WR_MASK_CLR, CLEAR);
	CSL_FINST(emifaRegs->INTMSKCLR, EMIFA_INTMSKCLR_LT_MASK_CLR, CLEAR);
	CSL_FINST(emifaRegs->INTMSKCLR, EMIFA_INTMSKCLR_AT_MASK_CLR, CLEAR);

	// Disables the extended wait cycles
	CSL_FINST(emifaRegs->CE2CFG, EMIFA_CE2CFG_EW, EXT_WAIT_DISABLE);

	// Configure the EMIFA Async timings
	{
		/*volatile EMIFATimingInfo_t *emifaTimingInfo = &emifDaqConfig;
		unsigned int wtTimeConf = 0;*/

		// Select the async interface opmode
		CSL_FINST(emifaRegs->CE2CFG, EMIFA_CE2CFG_SS, SELSTRB_ENABLE);

		// Configure the EMIFA Async timings
		CSL_FINS(emifaRegs->CE2CFG, EMIFA_CE2CFG_R_STROBE, 0);
		CSL_FINS(emifaRegs->CE2CFG, EMIFA_CE2CFG_R_HOLD, 0);
		CSL_FINS(emifaRegs->CE2CFG, EMIFA_CE2CFG_R_SETUP, 0);

		CSL_FINS(emifaRegs->CE2CFG, EMIFA_CE2CFG_W_STROBE, 1);
		CSL_FINS(emifaRegs->CE2CFG, EMIFA_CE2CFG_W_HOLD, 1);
		CSL_FINS(emifaRegs->CE2CFG, EMIFA_CE2CFG_W_SETUP, 0);

		CSL_FINS(emifaRegs->CE2CFG, EMIFA_CE2CFG_TA, 0);
	}

	// set the buswidth of async device
	CSL_FINST(emifaRegs->CE2CFG, EMIFA_CE2CFG_ASIZE, 8BIT);

}/* setup_EMIFA */
/*---------------------------------------------------------------------------*/

static void setup_EDMA (void)
{
	// Clear Event Registers
	CSL_FINST(edma3ccRegs->ECR, EDMA3CC_ECR_REG, MASK);
	CSL_FINST(edma3ccRegs->SECR, EDMA3CC_SECR_REG, MASK);
	
	// Enable Channel 10 to DSP (Region 1)
	CSL_FINST(edma3ccRegs->DRA[CSL_EDMA3_REGION_1].DRAE,
				EDMA3CC_DRAE_E10, ENABLE);
	
	// Assign Channel 10 to Queue 0
	CSL_FINST(edma3ccRegs->DMAQNUM[1], EDMA3CC_DMAQNUM_E2, Q0);
	
	// Initialize PaRAM Transfer Context for Event 10
	init_PaRAM_event10();
	
	// Enable Channel 10 Event Register
	CSL_FINST(edma3ccRegs->EESR, EDMA3CC_EESR_E10, SET);
	
	// Enable Interrupts for Channel 10
	CSL_FINST(edma3ccRegs->IESR, EDMA3CC_IESR_I10, SET);
}/* setup_EDMA */

/*---------------------------------------------------------------------------*/

static void init_PaRAM_event10 (void)
{
	// Reset EDMA PaRAM OPT Register
	edma3ccRegs->PARAMSET[EDMA_EVENT10].OPT = CSL_EDMA3CC_OPT_RESETVAL;
	
	// Config PaRAM OPT (Enable TC Interrupt; Set TCC)
	edma3ccRegs->PARAMSET[EDMA_EVENT10].OPT = 
		CSL_FMKT(EDMA3CC_OPT_TCINTEN, ENABLE) |
		CSL_FMK(EDMA3CC_OPT_TCC, EDMA_EVENT10)|
		CSL_FMKT(EDMA3CC_OPT_SYNCDIM, 		ASYNC)			|
		/*CSL_FMKT(EDMA3CC_OPT_SYNCDIM, 		ABSYNC)			|*/
		CSL_FMKT(EDMA3CC_OPT_STATIC, 		STATIC);
	
	// Initialize EDMA Event Src and Dst Addresses
	edma3ccRegs->PARAMSET[EDMA_EVENT10].SRC = (Uint32)srcBufferP;
	edma3ccRegs->PARAMSET[EDMA_EVENT10].DST = (Uint32)dstBufferP;
	
	// Set EDMA Event PaRAM A,B,C CNT
	edma3ccRegs->PARAMSET[EDMA_EVENT10].A_B_CNT = 
		CSL_FMK(EDMA3CC_A_B_CNT_ACNT, A_CNT) |
		CSL_FMK(EDMA3CC_A_B_CNT_BCNT, B_CNT);
	edma3ccRegs->PARAMSET[EDMA_EVENT10].CCNT = C_CNT;
	
	// Set EDMA Event PaRAM SRC/DST BIDX
	edma3ccRegs->PARAMSET[EDMA_EVENT10].SRC_DST_BIDX = 
		CSL_FMK(EDMA3CC_SRC_DST_BIDX_SRCBIDX, SB_IDX) |
		CSL_FMK(EDMA3CC_SRC_DST_BIDX_DSTBIDX, DB_IDX);
	
	// Set EDMA Event PaRAM SRC/DST CIDX
	edma3ccRegs->PARAMSET[EDMA_EVENT10].SRC_DST_CIDX = 
		CSL_FMK(EDMA3CC_SRC_DST_CIDX_SRCCIDX, SC_IDX) |
		CSL_FMK(EDMA3CC_SRC_DST_CIDX_DSTCIDX, DC_IDX);
	
	// Set EDMA Event PaRAM LINK and BCNTRLD
	edma3ccRegs->PARAMSET[EDMA_EVENT10].LINK_BCNTRLD = 
		CSL_FMK(EDMA3CC_LINK_BCNTRLD_LINK, PaRAM_NULL_LINK) |
		CSL_FMK(EDMA3CC_LINK_BCNTRLD_BCNTRLD, B_CNTRLD);
}/* init_PaRAM_event10 */

/*---------------------------------------------------------------------------*/

static void setup_DSP_INTC (void)
{
	// Map EDMA3CC/Timer0:12 System interrupts to DSP INT4/5
	dspintcRegs->INTMUX1 =
		CSL_FMK(DSPINTC_INTMUX1_INTSEL4, CSL_INTC_EVENTID_EDMA3_0_CC0_INT1) |
		CSL_FMK(DSPINTC_INTMUX1_INTSEL5, CSL_INTC_EVENTID_T64P0_TINT12);
	
	// Assign the address of the IST to the IST pointer
	ISTP = (unsigned int)intcVectorTable;
	
	// Clear all CPU maskable interrupts
	ICR = DSPINTC_IST_ALL_MASK_INT;
	
	// Enable INT4-INT5 interrupts
	IER = DSPINTC_IST_NMI | DSPINTC_IST_INT4 | DSPINTC_IST_INT5;
}/* setup_DSP_INTC */

/*---------------------------------------------------------------------------*/

static void EDMA_event_trig_DSPexample (void)
{
	printf("Example: EDMA_event_trig_dspL138\n"
		   "Scope:\tEDMA triggered by Timer0:12 performs a 1kB internal "
		   "memory to memory transfer.\n"
		   "Begin...\n");
	
	// Initialize Transfer Src and Dst Buffers
	/*dataPointer = (Uint8*)srcBuffer;
	for(counter = 0; counter < (SRC_ARRAYS * SRC_ARRAY_SIZE); counter++)
		*dataPointer++ = (Uint8)counter;*/
	
	dataPointer = (Uint8*)dstBuffer;
	for(counter = 0; counter < (DST_ARRAYS * DST_ARRAY_SIZE); counter++)
		*dataPointer++ = 0;
	
	runExample = 1;
	
	// Intrinsic Function to Enable Interrupts
	_enable_interrupts();
	
	printf("\tEnabling Timer with 1 second period...\n");
	
	// Enable Timer1:12 Once (Trigger EDMA Event 10)
	//CSL_FINST(tmr0Regs->TCR, TMR_TCR_ENAMODE12, EN_ONCE);
	CSL_FINST(tmr0Regs->TCR, TMR_TCR_ENAMODE12, EN_CONT);

	int burstTimerCount = 0, loopCount=0;
	//for(burstTimerCount=0; burstTimerCount<3; burstTimerCount++)
	while(1)
	{

		// Wait for Event 10 Completion Interrupt
		while(runExample);
		runExample = 1;

		// Wait for A-Xfer done (not xFer complete yet!)
		//for(loopCount=0; loopCount<20; loopCount++);
	}

	// Disable Timer0:12
	CSL_FINST(tmr0Regs->TCR, TMR_TCR_ENAMODE12, DISABLE);
	
	// Intrinsic Function to Disable Interrupts
	_disable_interrupts();
	
	// Verify Transfer
	/*errorCount = verify_EDMA_xfer(
					XFER_BYTES,
					XFER_ARRAYS,
					XFER_FRAMES,
					SRC_ARRAY_SIZE,
					DST_ARRAY_SIZE,
					0,0,
					&srcBuffer[0][0],
					&dstBuffer[0][0],
					FALSE);*/
	
	if(errorCount == NO_ERRORS)
		printf("\tTransfer Success!\n");
	else
		printf("\tTransfer Fail!\n");
	
	printf("End of example!\n\n");
}/* EDMA_event_trig_DSPexample */


/*-----------------------------------------------------------------------------
 *
 * 							Interrupt Functions
 * 
 *---------------------------------------------------------------------------*/
interrupt void EDMA3CC_INT1_isr (void)
{
	Uint32 regIPR, IxBitMask, IxCounter;
	runExampleCount++;
	while(edma3ccRegs->IPR != 0)
	{
		// Read Interrupt Pending Register
		regIPR = edma3ccRegs->IPR;
		
		// Loop for Set Interrupt Pending Bit
		for(IxCounter = 0; IxCounter < 32; IxCounter++)
		{
			IxBitMask = 1 << IxCounter;
			if(regIPR & IxBitMask)
			{
				// Exit Example on Correct Interrupt
				if(IxCounter == EDMA_EVENT10)
					runExample = 0;
				else
					printf("Interrupt not supported!\n");
				
				// Clear Pending Interrupt
				edma3ccRegs->ICR = IxBitMask;
				break;
			}
		}
	}
}

// Need this for successful transfer
interrupt void Timer0_12_isr (void)
{
	printf("\tInitiating transfer...\n");
	runTimerCount++;
}

over 12 years ago

0 RandyP over 12 years ago

TI__Guru* 84110 points

Veronica,

Programming with only the Register-level CSL can be very challenging. You have to know every bit of every register that you are trying to handle.

There are a couple of helpful topics on the Wiki, where you can do a search for "programming edma" (no quotes) to find them. One discusses register-only programming and one discusses using the EDMA3 LLD (Low Level Driver). I highly recommend you try using the LLD to help abstract some of the details away, although this may not help you with deciding the values for some bit settings.

In the Training section of TI.com, there is a training video set for the C6474. Even though this is a different device with a different DSP core, it may be helpful for you to review, in particular, the EDMA3/QDMA/IDMA Module to help you understand some of the features and options available within the EDMA3 module. You can find the complete video set here.

The best source of detailed information on the EDMA3 is the EDMA3 User Guide. You can use it to learn all the details about each bit of each field. Make sure you understand why you have selected each bit the way that you have and what the effect will be.

Since it appears you are creating a learning tool, I do recommend you look at the EDMA3 video, study the PARAM registers (especially the OPT register), and perhaps let us know something about what you are going to be trying to do in your real application. ACNT=3 is an unusual value; not wrong or anything, but it is also not common in the DSP environment.

Regards,
RandyP

0 Veronica Getaz over 12 years ago in reply to RandyP

Prodigy 70 points

Randy,

Thank you for your answer.

Our system does not use any BIOS, so we mainly use the Starterware to configure the peripherals. Since the EDMA did not have the expected behaivour with the Starterware, we decided to give the rCSL a try. I am actually making some basic tests, this is why I use the example from the quick start of the rCSL.

Now for details about the example. We would like to synchronize our EMIF transfers via the EDMA. The aim is then to transfer 1 frame (C_CNT=1) of for example 1000 arrays (B_CNT=1000) of 1 byte transfer (A_CNT=1). We would like to synchronize each array(1 byte transfer) to a specific timer frequency.

With the attached example, we succeed to synchronize each frame (with A_CNT=1 or several) to the desired timer (which runs in continuous mode). This succeeds when transferring a single array (B_CNT=C_CNT=1). The EDMA_completion_ISR is then called after each frame transfer, as expected.

The problem comes when we transfer more than one array (A_CNT=any value, B_CNT>1). Each frame is still synchronized to the timer frequency, but the EDMA_completion_ISR is not called anymore. And this happens even if the transfers are made continuously (started by the timer), meaning the data transferred > B_CNT.

We suspect a misconfiguration, since the B_CNT value do not seem to change in the registers view.

Thank in advance again.

Veronica

0 RandyP over 12 years ago in reply to Veronica Getaz

TI__Guru* 84110 points

Veronica,

Why do you have OPT.STATIC set?

Try turning it off.

Regards,
RandyP

0 Veronica Getaz over 12 years ago in reply to RandyP

Prodigy 70 points

Dear Randy,

Thank you a lot for your help. This had indeed solved the weird behavior.

I actually set OPT.STATIC since my source address was static. But I can of course do this also with IDX set to zero.

I succeed now to run continuously by self-linking to the current param set. I am still having some problems when stopping the timer for some time in between transfers. But I think this will be solved soon with correct interrupt flag management.

Thank you a lot for your help.

Veronica

0 RandyP over 12 years ago in reply to Veronica Getaz

TI__Guru* 84110 points

Veronica,

Are you really self-linking? Or are you linking to a Link PaRAM set that has the same values as the original set of values?

Regards,
RandyP

0 Veronica Getaz over 12 years ago in reply to RandyP

Prodigy 70 points

RandyP,

I am self-linking. i.e, at the configuration of the EDMA transfer: in the link address, instead of NULL parameter link address, we link to the current PaRAM set.

So, instead of having:

edma3ccRegs->PARAMSET[EDMA_EVENT10].LINK_BCNTRLD = CSL_FMK(EDMA3CC_LINK_BCNTRLD_LINK, PaRAM_NULL_LINK);

we have:

edma3ccRegs->PARAMSET[EDMA_EVENT10].LINK_BCNTRLD = CSL_FMK(EDMA3CC_LINK_BCNTRLD_LINK, EDMA_EVENT10) ;

Thank you and regards,

Veronica

0 RandyP over 12 years ago in reply to Veronica Getaz

TI__Guru* 84110 points

Veronica,

I am not aware of many cases where self-linking is a useful thing to do. How is it working out for you?

Regards,
RandyP

0 Veronica Getaz over 12 years ago in reply to RandyP

Prodigy 70 points

RandyP,

We would like to transfer one frame of 1000 arrays of 1 byte (A_CNT=1, B_CNT=1000, C_CNT=1). After the transfer (when EDMA completion ISR is called), we stop the transfer, treat the data, and then trigger again the EDMA transfer.

So we thought doing this with self-linking (perform again the same transfer). As well as by stopping the timer in between desired transfers. Would you suggest a better configuration for this behavior?

The self-linking works fine. We are still having some troubles stopping the EDMA transfer by simply disabling the timer in-between transfers.

Thank you and regards,

Veronica

0 RandyP over 12 years ago in reply to Veronica Getaz

TI__Guru* 84110 points

Veronica,

If it is working and you have that part of the application worked out, we are all glad for your success. Good work with the process and the good understanding that you have of the device.

Regards,
RandyP

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C674x Edma configuration