## GPIO toggle

The example is used to toggle gpio.

+ Select GPIO Portx
  ```
  // at main.c
  /**
   *  Select toggle pin
   */
  #define GPIO_PORTx  GPIOA
  #define GPIO_Pinx   GPIO_Pin_00
  ```

Note:
---
* If you want to toggle `PB1`, set IO to normal IO.(RST pin by default)
  ```
  SYSCFG_SetRstPin2NormalIO(true);   // set RST IO to normal IO
  ```
* If you want to toggle `PB[2:5]`, set IO to normal IO, and Restore IO to JTAG IO at the end.(JTAG pin by default)
  ```
  SYSCFG_SetICEPin2NormalIO(true);   // set JTAG IO to normal IO
  SYSCFG_SetICEPin2NormalIO(false);  // set normal IO to JTAG IO
  ```