tmk_core/tool/mbed/mbed-sdk/libraries/mbed/api/BusIn.h

   1 /* mbed Microcontroller Library
   2  * Copyright (c) 2006-2013 ARM Limited
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 #ifndef MBED_BUSIN_H
  17 #define MBED_BUSIN_H
  18
  19 #include "platform.h"
  20 #include "DigitalIn.h"
  21
  22 namespace mbed {
  23
  24 /** A digital input bus, used for reading the state of a collection of pins
  25  */
  26 class BusIn {
  27
  28 public:
  29     /* Group: Configuration Methods */
  30
  31     /** Create an BusIn, connected to the specified pins
  32      *
  33      * @param <n> DigitalIn pin to connect to bus bit <n> (p5-p30, NC)
  34      *
  35      * @note
  36      *  It is only required to specify as many pin variables as is required
  37      *  for the bus; the rest will default to NC (not connected)
  38      */
  39     BusIn(PinName p0, PinName p1 = NC, PinName p2 = NC, PinName p3 = NC,
  40           PinName p4 = NC, PinName p5 = NC, PinName p6 = NC, PinName p7 = NC,
  41           PinName p8 = NC, PinName p9 = NC, PinName p10 = NC, PinName p11 = NC,
  42           PinName p12 = NC, PinName p13 = NC, PinName p14 = NC, PinName p15 = NC);
  43
  44     BusIn(PinName pins[16]);
  45
  46     virtual ~BusIn();
  47
  48     /** Read the value of the input bus
  49      *
  50      *  @returns
  51      *   An integer with each bit corresponding to the value read from the associated DigitalIn pin
  52      */
  53     int read();
  54
  55     /** Set the input pin mode
  56      *
  57      *  @param mode PullUp, PullDown, PullNone
  58      */
  59     void mode(PinMode pull);
  60
  61     /** Binary mask of bus pins connected to actual pins (not NC pins)
  62      *  If bus pin is in NC state make corresponding bit will be cleared (set to 0), else bit will be set to 1
  63      *
  64      *  @returns
  65      *    Binary mask of connected pins
  66      */
  67     int mask() {
  68         return _nc_mask;
  69     }
  70
  71 #ifdef MBED_OPERATORS
  72     /** A shorthand for read()
  73      */
  74     operator int();
  75
  76     /** Access to particular bit in random-iterator fashion
  77      */
  78     DigitalIn & operator[] (int index);
  79 #endif
  80
  81 protected:
  82     DigitalIn* _pin[16];
  83
  84     /** Mask of bus's NC pins
  85      * If bit[n] is set to 1 - pin is connected
  86      * if bit[n] is cleared - pin is not connected (NC)
  87      */
  88     int _nc_mask;
  89
  90     /* disallow copy constructor and assignment operators */
  91 private:
  92     BusIn(const BusIn&);
  93     BusIn & operator = (const BusIn&);
  94 };
  95
  96 } // namespace mbed
  97
  98 #endif