text: /**
   * @author Neo Xu (neo.xu1990@gmail.com)
   * @license The MIT License (MIT)
   * 
   * Copyright (c) 2019 Neo Xu
   * 
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   * 
   * The above copyright notice and this permission notice shall be included in all
   * copies or substantial portions of the Software.
   * 
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
   * SOFTWARE.
   * 
  */
  #ifndef _FIFO_H_
  #define _FIFO_H_
  #include "stm8s.h"
  
  #define FIFO_DIS_INT() disableInterrupts() //disable interrupt
  #define FIFO_EN_INT()  enableInterrupts() //enable interrupt again.
  
  typedef enum
  {
  	fifo_err_ok = 0,
  	fifo_err_full = -1,
  	fifo_err_empty = -2,
    fifo_err_nullp = -3,  //null pointer provided.
  }fifo_err_def;
  
  typedef struct
  {
    uint8_t *pbuff;
    uint32_t buff_size;
    uint32_t write_index;
    uint32_t read_index;
    uint32_t data_count;
  }fifo_def;
  
  void fifo_init(fifo_def *pfifo, uint8_t *pbuff, uint32_t len);
  uint32_t fifo_status(fifo_def *pfifo);
  fifo_err_def fifo_write1B(fifo_def *pfifo, uint8_t ch);
  fifo_err_def fifo_read1B(fifo_def *pfifo, uint8_t *ch);
  fifo_err_def fifo_write(fifo_def *pfifo, uint8_t *pbuff, uint32_t *plen);
  fifo_err_def fifo_read(fifo_def *pfifo, uint8_t *pbuff, uint32_t *plen);
  
  #endif
  