DMAのテスト

うまくいったっぽいけど、このHLSが何をやっているか理解していなかった
https://forums.xilinx.com/t5/Vivado-High-Level-Synthesis-HLS/Problem-with-AXI-Stream-write-in-Vivado-HLS/td-p/712975
HLS

#include <string.h>


void topFunc(volatile char *a){

#pragma HLS INTERFACE m_axi depth=2000 port=a offset=slave
#pragma HLS INTERFACE s_axilite port=return bundle=AXILiteS
	int i;
	char buff[2000];
	memcpy(buff,(const char*)a,2000);
	for (int i = 0; i < 2000; i++) {
		buff[i] = buff[i]+10;
	}
	memcpy((char *)a,buff,2000);
}

BD

SDK

#include <stdio.h>
#include "platform.h"
#include "xil_printf.h"
#include "xtopfunc.h"

#define SIZE 20480

u32 *test;
u32 *test2;
XTopfunc xTopfunc;

int main()
{
  //init platform and the axi lite driver that is generated by the synthesis
  xil_printf("\r\n----------PROGRAM ENDED.-------------------\r\n");

  xil_printf("array size: %d\r\n",SIZE);

  Xil_DCacheEnable();

  int Status;
  Status = XTopfunc_Initialize(&xTopfunc, XPAR_TOPFUNC_0_DEVICE_ID);
  if (Status != XST_SUCCESS){
	  return XST_FAILURE;
  }

  for(int i=0;i<SIZE;i++){
    test[i] = 1;
  }

  XTopfunc_Set_a(&xTopfunc, test); //set the data to process

  Xil_DCacheFlush();

  //wait if interrupt appears, so the processing is done

  //enable interrupts and call the delivered *_start function
  xil_printf("Receive via DMA.\r\n");
  test2 = XTopfunc_Get_a(&xTopfunc); //get the results
  Xil_DCacheInvalidate();

  for(int i=0;i<SIZE;i++){
	  if(test[i]!=test2[i])
		  xil_printf("DMA test failed\r\n");
  }
  xil_printf("DMA test success.\r\n");
  xil_printf("----------PROGRAM ENDED.-------------------\r\n");

  cleanup_platform();
  return 0;
}

----------PROGRAM ENDED.-------------------
array size: 32
Receive via DMA.
DMA test success.
----------PROGRAM ENDED.-------------------

----------PROGRAM ENDED.-------------------
array size: 256
Receive via DMA.
DMA test success.
----------PROGRAM ENDED.-------------------

----------PROGRAM ENDED.-------------------
array size: 4096
Receive via DMA.
DMA test success.
----------PROGRAM ENDED.-------------------

----------PROGRAM ENDED.-------------------
array size: 65536

----------PROGRAM ENDED.-------------------
array size: 4097
Receive via DMA.
DMA test success.
----------PROGRAM ENDED.-------------------

----------PROGRAM ENDED.-------------------
array size: 20480
Receive via DMA.
DMA test success.
----------PROGRAM ENDED.-------------------