How to action on VTABufferCopy?

Hi. I wonder how the VTABufferCopy function works. We found that the VTA architecture loads data from Dram to Gram (buf) into a 2D access pattern. For example

DataBuffer* input_buf = (DataBuffer*)VTABufferAlloc( 16); VTABufferCopy(input, 0, input_buf, 0, sizeof(input), 1); VTALoadBuffer2D(vtaCmdH, input_buf, 0, 1, 1, 1, 0, 0, 0, 0, INP_IDX, 2);

I wonder what the role of VTABufferCopy is when these api are said to be played.