PS read data from DRAM

Question

Hi,

I got PL writting data to DRAM (I am using full AXI master to directly write data to DRAM). So far I was loading data back to PS by Xil_in32, is there some more efficient way to obtain big chunks of data from DRAM ?

Lets say I got array 256x256 of bytes in DRAM, how shall I load them to PS ? Or how do I efficiently access the data ?

EDIT:
ZedBoard, Bare-Metal

zedhed · Accepted Answer

Hi MartinGaraj,

Please correct me if I am wrong but I think when you say DRAM, you mean the DDR3 DRAM that the PS already has access to.

Are you just looking for another way to access the data so that you don't have to make calls to Xil_in32() when you want to access that memory space?

If so, let's say your data is located at 0x00200000 in DDR3 memory you should be able to declare a base memory address which points to the memory location of your matrix data:

#define BIG_MATRIX_BASE_ADDRESS (0x00200000)

Then declare a pointer to that memory space:

uint32_t *big_matrix = (uint32_t *) BIG_MATRIX_BASE;

Then use your pointer to access that memory space as if it were an array so that you can perform array operations on it from the PS:

for (long index = 0; index < (256*256); index++);
{
big_matrix[index] += 1;
}

Regards,

-Kevin

PS read data from DRAM

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