Problem with STM32 DAC

Hi everyone...

I'm a beginner and i'm trying to generate an Esclator signal from STM32f10e-eval's DAC, witch is configured, i suppose :), to be triggered by TIM3 TRGO trigger...but in debug mode nothing comes from the Logic Analyzer...what's wrong?

here is the main code:

/* Includes ------------------------------------------------------------------*/
#include "stm32f10x.h"

/** @addtogroup STM32F10x_StdPeriph_Examples
  * @{
  */

/** @addtogroup DAC_OneChannelDMA_Escalator
  * @{
  */

/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
#define DAC_DHR8R1_Address      0x40007410

/* Init Structure definition */
DAC_InitTypeDef            DAC_InitStructure;
DMA_InitTypeDef            DMA_InitStructure;
TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
TIM_ICInitTypeDef  TIM_ICInitStructure;
TIM_OCInitTypeDef  TIM_OCInitStructure;
uint16_t PrescalerValue = 0;

/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
const uint8_t Escalator8bit[6] = {0x0, 0x33, 0x66, 0x99, 0xCC, 0xFF};

/* Private function prototypes -----------------------------------------------*/
void RCC_Configuration(void);
void GPIO_Configuration(void);
void Delay(__IO uint32_t nCount);

/* Private functions ---------------------------------------------------------*/

/**
  * @brief   Main program.
  * @param  None
  * @retval None
  */
int main(void)
{
  /*!< At this stage the microcontroller clock setting is already configured,
       this is done through SystemInit() function which is called from startup
       file (startup_stm32f10x_xx.s) before to branch to application main.
       To reconfigure the default setting of SystemInit() function, refer to
       system_stm32f10x.c file
     */

  /* System Clocks Configuration */
  RCC_Configuration();

  /* Once the DAC channel is enabled, the corresponding GPIO pin is automatically
     connected to the DAC converter. In order to avoid parasitic consumption,
     the GPIO pin should be configured in analog */
  GPIO_Configuration();

  /* Compute the prescaler value */
  PrescalerValue = (uint16_t) (SystemCoreClock / 24000000) - 1;
  /* Time base configuration */
  TIM_TimeBaseStructure.TIM_Period = 65535;
  TIM_TimeBaseStructure.TIM_Prescaler = PrescalerValue;
  TIM_TimeBaseStructure.TIM_ClockDivision = 0;
  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;

  TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);

  /* TIM3 ToggleMode configuration: Channel1 */
  TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Toggle;
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
  TIM_OCInitStructure.TIM_Pulse = 16383;
  TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;

  TIM_OC1Init(TIM3, &TIM_OCInitStructure);


  /* TIM3 TRGO selection */
  TIM_SelectOutputTrigger(TIM3, TIM_TRGOSource_Update);

  /* DAC channel1 Configuration */
  DAC_InitStructure.DAC_Trigger = DAC_Trigger_T3_TRGO;
  DAC_InitStructure.DAC_WaveGeneration = DAC_WaveGeneration_None;
  DAC_InitStructure.DAC_OutputBuffer = DAC_OutputBuffer_Disable;
  DAC_Init(DAC_Channel_1, &DAC_InitStructure);

#if !defined STM32F10X_LD_VL && !defined STM32F10X_MD_VL
  /* DMA2 channel3 configuration */
  DMA_DeInit(DMA2_Channel3);
#else
  /* DMA1 channel3 configuration */
  DMA_DeInit(DMA1_Channel3);
#endif

  DMA_InitStructure.DMA_PeripheralBaseAddr = DAC_DHR8R1_Address;
  DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)&Escalator8bit;
  DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;
  DMA_InitStructure.DMA_BufferSize = 6;
  DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
  DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
  DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;
  DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;
  DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;
  DMA_InitStructure.DMA_Priority = DMA_Priority_High;
  DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;

#if !defined STM32F10X_LD_VL && !defined STM32F10X_MD_VL
  DMA_Init(DMA2_Channel3, &DMA_InitStructure);
  /* Enable DMA2 Channel3 */
  DMA_Cmd(DMA2_Channel3, ENABLE);
#else
  DMA_Init(DMA1_Channel3, &DMA_InitStructure);
  /* Enable DMA1 Channel3 */
  DMA_Cmd(DMA1_Channel3, ENABLE);
#endif

  /* Enable DAC Channel1: Once the DAC channel1 is enabled, PA.04 is
     automatically connected to the DAC converter. */
  DAC_Cmd(DAC_Channel_1, ENABLE);

  /* Enable DMA for DAC Channel1 */
  DAC_DMACmd(DAC_Channel_1, ENABLE);

  /* TIM3 enable counter */
  TIM_Cmd(TIM3, ENABLE);

  while (1)
  {
        ;
  }
}


/**
  * @brief  Configures the different system clocks.
  * @param  None
  * @retval None
  */
void RCC_Configuration(void)
{
  /* Enable peripheral clocks ------------------------------------------------*/
#if !defined STM32F10X_LD_VL && !defined STM32F10X_MD_VL
  /* DMA2 clock enable */
  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA2, ENABLE);
#else
  /* DMA1 clock enable */
  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);
#endif
  /* GPIOA Periph clock enable */
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
  /* DAC Periph clock enable */
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_DAC, ENABLE);
  /* TIM6 Periph clock enable */
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
}

/**
  * @brief  Configures the different GPIO ports.
  * @param  None
  * @retval None
  */
void GPIO_Configuration(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;

  /* Once the DAC channel is enabled, the corresponding GPIO pin is automatically
     connected to the DAC converter. In order to avoid parasitic consumption,
     the GPIO pin should be configured in analog */
  GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_4;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;
  GPIO_Init(GPIOA, &GPIO_InitStructure);
}

/**
  * @brief  Inserts a delay time.
  * @param  nCount: specifies the delay time length.
  * @retval None
  */
void Delay(__IO uint32_t nCount)
{
  for(; nCount != 0; nCount--);
}

#ifdef  USE_FULL_ASSERT

/**
  * @brief  Reports the name of the source file and the source line number
  *         where the assert_param error has occurred.
  * @param  file: pointer to the source file name
  * @param  line: assert_param error line source number
  * @retval None
  */
void assert_failed(uint8_t* file, uint32_t line)
{
  /* User can add his own implementation to report the file name and line number,
     ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */

  /* Infinite loop */
  while (1)
  {
  }
}
#endif