text: /*!
      \file  main.c
      \brief communication_among_CANS in normal mode
      
      \version 2014-12-26, V1.0.0, firmware for GD32F10x
      \version 2017-06-20, V2.0.0, firmware for GD32F10x
      \version 2018-07-31, V2.1.0, firmware for GD32F10x
  */
  
  /*
      Copyright (c) 2018, GigaDevice Semiconductor Inc.
  
      All rights reserved.
  
      Redistribution and use in source and binary forms, with or without modification, 
  are permitted provided that the following conditions are met:
  
      1. Redistributions of source code must retain the above copyright notice, this 
         list of conditions and the following disclaimer.
      2. Redistributions in binary form must reproduce the above copyright notice, 
         this list of conditions and the following disclaimer in the documentation 
         and/or other materials provided with the distribution.
      3. Neither the name of the copyright holder nor the names of its contributors 
         may be used to endorse or promote products derived from this software without 
         specific prior written permission.
  
      THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 
  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 
  IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 
  INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 
  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 
  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 
  WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
  OF SUCH DAMAGE.
  */
  
  #include "gd32f10x.h"
  #include <stdio.h>
  #include "gd32f10x_eval.h"
  
  /* select CAN baudrate */
  /* 1MBps */
  #define CAN_BAUDRATE  1000
  /* 500kBps */
  /* #define CAN_BAUDRATE  500 */
  /* 250kBps */
  /* #define CAN_BAUDRATE  250 */
  /* 125kBps */
  /* #define CAN_BAUDRATE  125 */
  /* 100kBps */ 
  /* #define CAN_BAUDRATE  100 */
  /* 50kBps */ 
  /* #define CAN_BAUDRATE  50 */
  /* 20kBps */ 
  /* #define CAN_BAUDRATE  20 */
  
  FlagStatus can0_receive_flag;
  FlagStatus can1_receive_flag;
  FlagStatus can0_error_flag;
  FlagStatus can1_error_flag;
  can_parameter_struct can_init_parameter;
  can_filter_parameter_struct can_filter_parameter;
  can_trasnmit_message_struct transmit_message;
  can_receive_message_struct receive_message;
  
  void nvic_config(void);
  void led_config(void);
  void can_gpio_config(void);
  void can_config(can_parameter_struct can_parameter, can_filter_parameter_struct can_filter);
  
  /*!
      \brief      main function
      \param[in]  none
      \param[out] none
      \retval     none
  */
  int main(void)
  {
      can0_receive_flag = RESET;
      can1_receive_flag = RESET;
      can0_error_flag = RESET;
      can1_error_flag = RESET;
      
      /* configure GPIO */
      can_gpio_config();
      
      /* configure NVIC */
      nvic_config();
      
      /* configure USART */
      gd_eval_com_init(EVAL_COM0);
      
      /* configure Wakeup key or Tamper key */
      gd_eval_key_init(KEY_WAKEUP, KEY_MODE_GPIO);
      gd_eval_key_init(KEY_TAMPER, KEY_MODE_GPIO);
      
      printf("\r\nGD32F10x dual CAN test, please press Wakeup key or Tamper key to start communication!\r\n");
      /* configure leds */
      led_config();
      gd_eval_led_off(LED2);
      gd_eval_led_off(LED3);
      gd_eval_led_off(LED4);
      gd_eval_led_off(LED5);
      
      /* initialize CAN and filter */
      can_config(can_init_parameter, can_filter_parameter);
      /* enable can receive FIFO0 not empty interrupt */
      can_interrupt_enable(CAN0, CAN_INT_RFNE0);
      can_interrupt_enable(CAN1, CAN_INT_RFNE0);
      
      /* initialize transmit message */
      transmit_message.tx_sfid = 0x300>>1;
      transmit_message.tx_efid = 0x00;
      transmit_message.tx_ft = CAN_FT_DATA;
      transmit_message.tx_ff = CAN_FF_STANDARD;
      transmit_message.tx_dlen = 2;
  
      while(1){
          /* test whether the Tamper key is pressed */
          if(0 == gd_eval_key_state_get(KEY_TAMPER)){
              transmit_message.tx_data[0] = 0x55;
              transmit_message.tx_data[1] = 0xAA;
              printf("\r\n can0 transmit data:%x,%x", transmit_message.tx_data[0], transmit_message.tx_data[1]);
              /* transmit message */
              can_message_transmit(CAN0, &transmit_message);
              /* waiting for the Tamper key up */
              while(0 == gd_eval_key_state_get(KEY_TAMPER));
          }
          /* test whether the Wakeup key is pressed */
          if(0 == gd_eval_key_state_get(KEY_WAKEUP)){
              transmit_message.tx_data[0] = 0xAA;
              transmit_message.tx_data[1] = 0x55;
              printf("\r\n can1 transmit data:%x,%x", transmit_message.tx_data[0], transmit_message.tx_data[1]);
              /* transmit message */
              can_message_transmit(CAN1, &transmit_message);
              /* waiting for the Wakeup key up */
              while(0 == gd_eval_key_state_get(KEY_WAKEUP));
          }
          /* CAN0 receive data correctly, the received data is printed */
          if(SET == can0_receive_flag){
              can0_receive_flag = RESET;
              printf("\r\n can0 receive data:%x,%x", receive_message.rx_data[0], receive_message.rx_data[1]);
              gd_eval_led_toggle(LED4);
          }
          /* CAN1 receive data correctly, the received data is printed */
          if(SET == can1_receive_flag){
              can1_receive_flag = RESET;
              gd_eval_led_toggle(LED5);
              printf("\r\n can1 receive data:%x,%x", receive_message.rx_data[0], receive_message.rx_data[1]);
          }
          /* CAN0 error */
          if(SET == can0_error_flag){
              can0_error_flag = RESET;
              printf("\r\n can0 communication error");
          }
          /* CAN1 error */
          if(SET == can1_error_flag){
              can1_error_flag = RESET;
              printf("\r\n can1 communication error");
          }
      }
  }
  
  /*!
      \brief      initialize CAN and filter
      \param[in]  can_parameter
        \arg        can_parameter_struct
      \param[in]  can_filter
        \arg        can_filter_parameter_struct
      \param[out] none
      \retval     none
  */
  void can_config(can_parameter_struct can_parameter, can_filter_parameter_struct can_filter)
  {
      can_struct_para_init(CAN_INIT_STRUCT, &can_parameter);
      can_struct_para_init(CAN_INIT_STRUCT, &can_filter);
      /* initialize CAN register */
      can_deinit(CAN0);
      can_deinit(CAN1);
      
      /* initialize CAN parameters */
      can_parameter.time_triggered = DISABLE;
      can_parameter.auto_bus_off_recovery = DISABLE;
      can_parameter.auto_wake_up = DISABLE;
      can_parameter.no_auto_retrans = DISABLE;
      can_parameter.rec_fifo_overwrite = DISABLE;
      can_parameter.trans_fifo_order = DISABLE;
      can_parameter.working_mode = CAN_NORMAL_MODE;
      can_parameter.resync_jump_width = CAN_BT_SJW_1TQ;
      can_parameter.time_segment_1 = CAN_BT_BS1_5TQ;
      can_parameter.time_segment_2 = CAN_BT_BS2_3TQ;
      
      /* 1MBps */
  #if CAN_BAUDRATE == 1000
      can_parameter.prescaler = 6;
      /* 500KBps */
  #elif CAN_BAUDRATE == 500
      can_parameter.prescaler = 12;
      /* 250KBps */
  #elif CAN_BAUDRATE == 250
      can_parameter.prescaler = 24;
      /* 125KBps */
  #elif CAN_BAUDRATE == 125
      can_parameter.prescaler = 48;
      /* 100KBps */
  #elif  CAN_BAUDRATE == 100
      can_parameter.prescaler = 60;
      /* 50KBps */
  #elif  CAN_BAUDRATE == 50
      can_parameter.prescaler = 120;
      /* 20KBps */
  #elif  CAN_BAUDRATE == 20
      can_parameter.prescaler = 300;
  #else
      #error "please select list can baudrate in private defines in main.c "
  #endif  
      /* initialize CAN */
      can_init(CAN0, &can_parameter);
      can_init(CAN1, &can_parameter);
      
      /* initialize filter */ 
      can_filter.filter_number=0;
      can_filter.filter_mode = CAN_FILTERMODE_MASK;
      can_filter.filter_bits = CAN_FILTERBITS_32BIT;
      can_filter.filter_list_high = 0x3000;
      can_filter.filter_list_low = 0x0000;
      can_filter.filter_mask_high = 0x3000;
      can_filter.filter_mask_low = 0x0000;
      can_filter.filter_fifo_number = CAN_FIFO0;
      can_filter.filter_enable = ENABLE;
      
      can_filter_init(&can_filter);
      
      /* CAN1 filter number */
      can_filter.filter_number = 15;
      can_filter_init(&can_filter);
  }
  
  /*!
      \brief      configure the nested vectored interrupt controller
      \param[in]  none
      \param[out] none
      \retval     none
  */
  void nvic_config(void)
  {
      /* configure CAN0 NVIC */
      nvic_irq_enable(CAN0_RX0_IRQn,0,0);
  
      /* configure CAN1 NVIC */
      nvic_irq_enable(CAN1_RX0_IRQn,1,1);
  }
  
  /*!
      \brief      configure the leds
      \param[in]  none
      \param[out] none
      \retval     none
  */
  void led_config(void)
  {
      gd_eval_led_init(LED2);
      gd_eval_led_init(LED3);
      gd_eval_led_init(LED4);
      gd_eval_led_init(LED5);
  }
  
  /*!
      \brief      configure GPIO
      \param[in]  none
      \param[out] none
      \retval     none
  */
  void can_gpio_config(void)
  {
      /* enable CAN clock */
      rcu_periph_clock_enable(RCU_CAN0);
      rcu_periph_clock_enable(RCU_CAN1);
      rcu_periph_clock_enable(RCU_GPIOB);
      rcu_periph_clock_enable(RCU_GPIOD);
      rcu_periph_clock_enable(RCU_AF);
      
      /* configure CAN0 GPIO */
      gpio_init(GPIOD,GPIO_MODE_IPU,GPIO_OSPEED_50MHZ,GPIO_PIN_0);
      gpio_init(GPIOD,GPIO_MODE_AF_PP,GPIO_OSPEED_50MHZ,GPIO_PIN_1);
      gpio_pin_remap_config(GPIO_CAN0_FULL_REMAP,ENABLE);
      
      /* configure CAN1 GPIO */
      gpio_init(GPIOB,GPIO_MODE_IPU,GPIO_OSPEED_50MHZ,GPIO_PIN_5);
      gpio_init(GPIOB,GPIO_MODE_AF_PP,GPIO_OSPEED_50MHZ,GPIO_PIN_6);
      gpio_pin_remap_config(GPIO_CAN1_REMAP,ENABLE);
  }
  
  /* retarget the C library printf function to the usart */
  int fputc(int ch, FILE *f)
  {
      usart_data_transmit(EVAL_COM0, (uint8_t)ch);
      while (RESET == usart_flag_get(EVAL_COM0, USART_FLAG_TBE));
      return ch;
  }
  