tmk_core/tool/mbed/mbed-sdk/libraries/mbed/api/BusOut.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_BUSOUT_H
  17 #define MBED_BUSOUT_H
  18
  19 #include "DigitalOut.h"
  20
  21 namespace mbed {
  22
  23 /** A digital output bus, used for setting the state of a collection of pins
  24  */
  25 class BusOut {
  26
  27 public:
  28
  29     /** Create an BusOut, connected to the specified pins
  30      *
  31      *  @param p<n> DigitalOut pin to connect to bus bit <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     BusOut(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     BusOut(PinName pins[16]);
  43
  44     virtual ~BusOut();
  45
  46     /** Write the value to the output bus
  47      *
  48      *  @param value An integer specifying a bit to write for every corresponding DigitalOut pin
  49      */
  50     void write(int value);
  51
  52     /** Read the value currently output on the bus
  53      *
  54      *  @returns
  55      *    An integer with each bit corresponding to associated DigitalOut pin setting
  56      */
  57     int read();
  58
  59     /** Binary mask of bus pins connected to actual pins (not NC pins)
  60      *  If bus pin is in NC state make corresponding bit will be cleared (set to 0), else bit will be set to 1
  61      *
  62      *  @returns
  63      *    Binary mask of connected pins
  64      */
  65     int mask() {
  66         return _nc_mask;
  67     }
  68
  69 #ifdef MBED_OPERATORS
  70     /** A shorthand for write()
  71      */
  72     BusOut& operator= (int v);
  73     BusOut& operator= (BusOut& rhs);
  74
  75     /** Access to particular bit in random-iterator fashion
  76      */
  77     DigitalOut& operator[] (int index);
  78
  79     /** A shorthand for read()
  80      */
  81     operator int();
  82 #endif
  83
  84 protected:
  85     DigitalOut* _pin[16];
  86
  87     /** Mask of bus's NC pins
  88      * If bit[n] is set to 1 - pin is connected
  89      * if bit[n] is cleared - pin is not connected (NC)
  90      */
  91     int _nc_mask;
  92
  93    /* disallow copy constructor and assignment operators */
  94 private:
  95     BusOut(const BusOut&);
  96     BusOut & operator = (const BusOut&);
  97 };
  98
  99 } // namespace mbed
 100
 101 #endif