Copy ram data to flash via DMA (CC2541)

Other Parts Discussed in Thread: CC2541

Hi, I'm programming a CC2541 device and I need to copy the content of a part of the ram to the flash memory. I must do it without high level libraries (has HAL or OSAL) so I did this code:

/******************************************************************************
* INCLUDES
*/
#include <ioCC2541.h>
#include <stdlib.h> 

/******************************************************************************
* DEFINES
*/
#define INIT_RAM 0x0C00
#define INIT_FLASH 0xC000
#define COPY_LEN 512 // 256x8b = 4k = 4096b

//! Low nibble of 16bit variable
#define LOBYTE(w)           ((unsigned char)(w))
//! High nibble of 16bit variable
#define HIBYTE(w)           ((unsigned char)(((unsigned short)(w) >> 8) & 0xFF))


/******************************************************************************
* FUNCIONES     
*/
void programmer_init(void)
{
  // Switch programmer (a CC2530) to 32 MHz XOSC for max performance
  CLKCONCMD = 0x80;
  while (CLKCONSTA != 0x80);
}

/**************************************************************************//**
* @brief    Main function.
*
* @return   None.
******************************************************************************/
void main(void)
{
  asm("nop"); // For debugging.
  programmer_init();
  
  unsigned char * mem = (unsigned char *) INIT_RAM;
  mem[0]='H';
  mem[1]='E';
  mem[2]='L';
  mem[3]='L';
  mem[4]='O';
  
  
  MEMCTR = 0x08;
  
    //Start Flash Page 0xC1 erase.
    EA=0;
    FADDRH=HIBYTE(INIT_FLASH)+1; 
    FCTL|=0x01; //Erase with cache
    while (FCTL & 0x80);  // Wait until writing is done.
    
    //Start Flash Page 0xC0 erase.
    FADDRH=HIBYTE(INIT_FLASH); 
    FCTL|=0x01; //Erase with cache
    while (FCTL & 0x80);  // Wait until writing is done.
    EA=1;
  
  
  //SETUP DMA Controller.
  unsigned char * dma_desc_0 = (unsigned char *)0x1f00;
  dma_desc_0[7]=HIBYTE(INIT_RAM);           // src[15:8]
  dma_desc_0[6]=LOBYTE(INIT_RAM);           // src[7:0]
  dma_desc_0[5]=HIBYTE(FWDATA);           // dest[15:8]
  dma_desc_0[4]=LOBYTE(FWDATA);           // dest[7:0]
  dma_desc_0[3]=HIBYTE(COPY_LEN);            // len[12:8] 
  dma_desc_0[2]=LOBYTE(COPY_LEN);             // len[7:0]
  dma_desc_0[1]=0x12;                 
  dma_desc_0[0]=0x4A; 
  
  DMA0CFGH = HIBYTE(dma_desc_0); 
  DMA0CFGL = LOBYTE(dma_desc_0); 
  
  //SETUP Flash Controller.
  FADDRH=HIBYTE(INIT_FLASH); 
  FADDRL=LOBYTE(INIT_FLASH); 
  
  
  //ARM DMA Channel.
  DMAARM=1; //Arm Channel 0.
  
  //Arm Process takes 9 System Clocks.
  for(int i=0;i<11;i++){
    asm("nop");
  }
  
  //Start Flash Write.
  FCTL = 0x06; //FCTL |= 0x02;         // Trigger the DMA writes.
  
  // Wait until writing is done.
  
  while (FCTL & 0x80){
    asm("nop");
  }
 
  // Infinite loop
  while(1){
    asm("nop");
  }
}

I don't really know why it's not working because nothing is copied to flash. I've spent several hours trying to find out the mistake, and I need your help.

Thanks in advance.

Alfred.