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Question about the source codes of the "Off chip delay" module

Question asked by liangbread on May 29, 2014
Latest reply on Jun 9, 2014 by JJoseph

Hi John,

As needed,I have to modify the source codes of the "Off chip delay".Referring to the source codes,I got question about the memory size the delay module populates in off-chip SDRAM.We may look at the following cods first.

 

/*Reset the SDRAM buffer*/

        memset((void *)pParamIntPtr[1], 0, pOffchipDelay->nExternalBufferLength * nChannels);


I would consider the size used for the memset function should be twice the size of the present one.Because every single audio data sample is supposed to be float_32 which means it would populate 4 bytes of 32bit.But the SDRAM interfacing to the ADSP-21489 is only 16 bit width,which means the storage cell of it is 2 bytes of 16 bit.

 

Here I question about

1)How many bytes are set to "0" by that memset function?

2)If I write the value of 0xFFFFFFFF(32bit) to the off-chip address 0x00220000,will it overflow to the the off-chip address 0x00220001 actually?

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