text: /* mbed Microcontroller Library
   * Copyright (c) 2006-2013 ARM Limited
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  #ifndef MBED_BUSIN_H
  #define MBED_BUSIN_H
  
  #include "platform.h"
  #include "DigitalIn.h"
  
  namespace mbed {
  
  /** A digital input bus, used for reading the state of a collection of pins
   */
  class BusIn {
  
  public:
      /* Group: Configuration Methods */
  
      /** Create an BusIn, connected to the specified pins
       *
       * @param <n> DigitalIn pin to connect to bus bit <n> (p5-p30, NC)
       *
       * @note
       *  It is only required to specify as many pin variables as is required
       *  for the bus; the rest will default to NC (not connected)
       */
      BusIn(PinName p0, PinName p1 = NC, PinName p2 = NC, PinName p3 = NC,
            PinName p4 = NC, PinName p5 = NC, PinName p6 = NC, PinName p7 = NC,
            PinName p8 = NC, PinName p9 = NC, PinName p10 = NC, PinName p11 = NC,
            PinName p12 = NC, PinName p13 = NC, PinName p14 = NC, PinName p15 = NC);
  
      BusIn(PinName pins[16]);
  
      virtual ~BusIn();
  
      /** Read the value of the input bus
       *
       *  @returns
       *   An integer with each bit corresponding to the value read from the associated DigitalIn pin
       */
      int read();
  
      /** Set the input pin mode
       *
       *  @param mode PullUp, PullDown, PullNone
       */
      void mode(PinMode pull);
  
      /** Binary mask of bus pins connected to actual pins (not NC pins)
       *  If bus pin is in NC state make corresponding bit will be cleared (set to 0), else bit will be set to 1
       *
       *  @returns
       *    Binary mask of connected pins
       */
      int mask() {
          return _nc_mask;
      }
  
  #ifdef MBED_OPERATORS
      /** A shorthand for read()
       */
      operator int();
  
      /** Access to particular bit in random-iterator fashion
       */
      DigitalIn & operator[] (int index);
  #endif
  
  protected:
      DigitalIn* _pin[16];
  
      /** Mask of bus's NC pins
       * If bit[n] is set to 1 - pin is connected
       * if bit[n] is cleared - pin is not connected (NC)
       */
      int _nc_mask;
  
      /* disallow copy constructor and assignment operators */
  private:
      BusIn(const BusIn&);
      BusIn & operator = (const BusIn&);
  };
  
  } // namespace mbed
  
  #endif
  