tmk_core/tool/mbed/mbed-sdk/libraries/mbed/api/BusInOut.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_BUSINOUT_H
  17 #define MBED_BUSINOUT_H
  18
  19 #include "DigitalInOut.h"
  20
  21 namespace mbed {
  22
  23 /** A digital input output bus, used for setting the state of a collection of pins
  24  */
  25 class BusInOut {
  26
  27 public:
  28
  29     /** Create an BusInOut, connected to the specified pins
  30      *
  31      *  @param p<n> DigitalInOut pin to connect to bus bit p<n> (p5-p30, NC)
  32      *
  33      *  @note
  34      *  It is only required to specify as many pin variables as is required
  35      *  for the bus; the rest will default to NC (not connected)
  36      */
  37     BusInOut(PinName p0, PinName p1 = NC, PinName p2 = NC, PinName p3 = NC,
  38              PinName p4 = NC, PinName p5 = NC, PinName p6 = NC, PinName p7 = NC,
  39              PinName p8 = NC, PinName p9 = NC, PinName p10 = NC, PinName p11 = NC,
  40              PinName p12 = NC, PinName p13 = NC, PinName p14 = NC, PinName p15 = NC);
  41
  42     BusInOut(PinName pins[16]);
  43
  44     virtual ~BusInOut();
  45
  46     /* Group: Access Methods */
  47
  48     /** Write the value to the output bus
  49      *
  50      *  @param value An integer specifying a bit to write for every corresponding DigitalInOut pin
  51      */
  52     void write(int value);
  53
  54     /** Read the value currently output on the bus
  55      *
  56      *  @returns
  57      *    An integer with each bit corresponding to associated DigitalInOut pin setting
  58      */
  59     int read();
  60
  61     /** Set as an output
  62      */
  63     void output();
  64
  65     /** Set as an input
  66      */
  67     void input();
  68
  69     /** Set the input pin mode
  70      *
  71      *  @param mode PullUp, PullDown, PullNone
  72      */
  73     void mode(PinMode pull);
  74
  75     /** Binary mask of bus pins connected to actual pins (not NC pins)
  76      *  If bus pin is in NC state make corresponding bit will be cleared (set to 0), else bit will be set to 1
  77      *
  78      *  @returns
  79      *    Binary mask of connected pins
  80      */
  81     int mask() {
  82         return _nc_mask;
  83     }
  84
  85 #ifdef MBED_OPERATORS
  86      /** A shorthand for write()
  87      */
  88     BusInOut& operator= (int v);
  89     BusInOut& operator= (BusInOut& rhs);
  90
  91     /** Access to particular bit in random-iterator fashion
  92     */
  93     DigitalInOut& operator[] (int index);
  94
  95     /** A shorthand for read()
  96      */
  97     operator int();
  98 #endif
  99
 100 protected:
 101     DigitalInOut* _pin[16];
 102
 103     /** Mask of bus's NC pins
 104      * If bit[n] is set to 1 - pin is connected
 105      * if bit[n] is cleared - pin is not connected (NC)
 106      */
 107     int _nc_mask;
 108
 109     /* disallow copy constructor and assignment operators */
 110 private:
 111     BusInOut(const BusInOut&);
 112     BusInOut & operator = (const BusInOut&);
 113 };
 114
 115 } // namespace mbed
 116
 117 #endif