disabled swd debuging

Hi,

i used to program my stm32 discovery board via usb cable using SWD. 

I used some example code and i think i disabled SWD debugging accidently. 

Now i cant enable it back, the Keil software i use says that no target is connected and flash download failed. Can anyone help me to enable SWD back ? Is there any ways to reset stm32. Here's the example code i used :

main.c

&sharpinclude ''stm32f10x_lib.h''

/* function prototypes */

void RCC_Configuration(void);

void GPIO_Configuration(void);

void Delay(vu32 nCount);

/* entry point */

int main(void)

{

  /* configure clock sources */

  RCC_Configuration();

  /* configure I/O ports */

  GPIO_Configuration();

  /* blinking loop */

  while (1) {

    /* change the PC7 state */

    GPIO_WriteBit(GPIOC, GPIO_Pin_8, (BitAction)(1 - GPIO_ReadOutputDataBit(GPIOC, GPIO_Pin_8)));

    /* wait */

    Delay(0x5FFFF);

    Delay(0x5FFFF);

    Delay(0x5FFFF);

    Delay(0x5FFFF);

    Delay(0x5FFFF);

    Delay(0x5FFFF);

  }

}

/* set up clock sources */

void RCC_Configuration(void)

{

  /* reset */

  RCC_DeInit();

  /* activate HSI (Internal High Speed oscillator) */

  RCC_HSICmd(ENABLE);

  while (RCC_GetFlagStatus(RCC_FLAG_HSIRDY) == RESET);

  /* configure prescalers */  

  RCC_HCLKConfig(RCC_SYSCLK_Div1);// HCLK = 64 MHz, AHB

  RCC_PCLK1Config(RCC_HCLK_Div2); // APB1 = 32 MHz

  RCC_PCLK2Config(RCC_HCLK_Div1); // APB2 = 64 MHz

  /* set up FLASH */

  FLASH_SetLatency(FLASH_Latency_2);

  FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable);

  /* set up PLL */

  RCC_PLLConfig(RCC_PLLSource_HSI_Div2, RCC_PLLMul_16); // 64 MHz

  RCC_PLLCmd(ENABLE);

  while (RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET);

  /* set up SYSCLK */

  RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK); //SYSCLK = PLLCLK => 64 MHz

  while (RCC_GetSYSCLKSource() != 0x08);

  /* set up peripheral clock */

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC | RCC_APB2Periph_AFIO, ENABLE); 

}        

/* configure I/O ports */

void GPIO_Configuration(void)

{

  /* pin configuration parameters */

  GPIO_InitTypeDef GPIO_InitStructure;

  /* disable SWJ debug port - comment if you are using JTAG */

 GPIO_PinRemapConfig(GPIO_Remap_SWJ_Disable, ENABLE);

  /* configure PC7 as output push-pull  */

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8;

  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_10MHz;

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;

  GPIO_Init(GPIOC, &GPIO_InitStructure);

}

/* wait */

void Delay(vu32 nCount)

{

  while (nCount--);

}