topic Re: How to disable DMA Address Alignment Checking? in Processor Expert Software

How to disable DMA Address Alignment Checking?

vitomarolda — Mon, 02 Nov 2020 13:22:39 GMT

Hi, I am using KL46Z SPI with DMA, and I do receive a block using the following code (which works flawlessly):

SPIMasterLDD_1_ReceiveBlock(SPIMasterLDD_1_TDD_Ptr,reg_data,cnt);
SPIMasterLDD_1_SendBlock(SPIMasterLDD_1_TDD_Ptr,reg_data,cnt);
while(SPIMasterLDD_1_GetBlockReceivedStatus(SPIMasterLDD_1_TDD_Ptr)==FALSE);

I use slow clock in order to save battery (core=8MHz).

I noticed a long delay (120us) before rx/tx, and I finally figured it out the delay is due to SetDestinationAddress/SetSourceAddress:

LDD_TError DMA1_SetSourceAddress(DMA1_TChanDeviceData *ChanDeviceDataPtr, LDD_DMA_TData *Address)
{
  /* This test can be disabled by setting the "Ignore state checking"
     property to the "yes" value in the "Configuration inspector" */
  if (((uint32_t)Address % GetTransactionUnitSize(((DMA1_TChnDevData *)ChanDeviceDataPtr)->TCDPtr)) != 0U) {
    return ERR_PARAM_ADDRESS;
  }
  DMA1__SetSrcAddress(((DMA1_TChnDevData *)ChanDeviceDataPtr)->TCDPtr, (uint32_t)Address);
  return ERR_OK;
}

they both perform a 32 bit modulo operation for preliminary address alignment checking. I would like to disable this test. Comment on the function states:

This test can be disabled by setting the "Ignore state checking" property to the "yes" value in the "Configuration inspector"

But such option does not exist on KDS3.0.0:

Does anybody know how to disable DMA Address Alignment checking?

Thank you in advance.

Best Regards.

Vito.

Re: How to disable DMA Address Alignment Checking?

Alice_Yang — Thu, 28 Jan 2016 07:42:30 GMT

Hello Vito,

I test it on my side , and under the function of " DMAT1_SetSourceAddress", there is not have the "test",

I use the KDS 3.0, only add the component of "DMATransfer_LDD" and almost do nothing.

And doest your code is generate on the KDS3.0 or porting if from other place ?

Alice

Re: How to disable DMA Address Alignment Checking?

marek_neuzil — Tue, 02 Feb 2016 12:27:54 GMT

Hello Vito,

I am sorry I have discussed the issue with the author of the driver and the comment is incorrect. There is not any Ignore state checking option in the Processor Expert.

You can modify the source code (remove the source code of checking) when you disable generating of these source code files by Processor Expert. Open the context menu of the component in the Component window and select Code Generation - Don't Write Generated Component Modules, see the screenshot below:

This option ensures that the source code of the DMA component will not be modified by Processor Expert (during Generate Processor Expert Code operation).

Best Regards,

Marek Neuzil