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BusOut.h
1 /* mbed Microcontroller Library
2  * Copyright (c) 2006-2013 ARM Limited
3  * SPDX-License-Identifier: Apache-2.0
4  *
5  * Licensed under the Apache License, Version 2.0 (the "License");
6  * you may not use this file except in compliance with the License.
7  * You may obtain a copy of the License at
8  *
9  * http://www.apache.org/licenses/LICENSE-2.0
10  *
11  * Unless required by applicable law or agreed to in writing, software
12  * distributed under the License is distributed on an "AS IS" BASIS,
13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  * See the License for the specific language governing permissions and
15  * limitations under the License.
16  */
17 #ifndef MBED_BUSOUT_H
18 #define MBED_BUSOUT_H
19 
20 #include "drivers/DigitalOut.h"
21 #include "platform/PlatformMutex.h"
22 #include "platform/NonCopyable.h"
23 
24 namespace mbed {
25 /** \addtogroup drivers */
26 
27 /** A digital output bus, used for setting the state of a collection of pins
28  * @ingroup drivers
29  */
30 class BusOut : private NonCopyable<BusOut> {
31 
32 public:
33 
34  /** Create an BusOut, connected to the specified pins
35  *
36  * @param p0 DigitalOut pin to connect to bus bit
37  * @param p1 DigitalOut pin to connect to bus bit
38  * @param p2 DigitalOut pin to connect to bus bit
39  * @param p3 DigitalOut pin to connect to bus bit
40  * @param p4 DigitalOut pin to connect to bus bit
41  * @param p5 DigitalOut pin to connect to bus bit
42  * @param p6 DigitalOut pin to connect to bus bit
43  * @param p7 DigitalOut pin to connect to bus bit
44  * @param p8 DigitalOut pin to connect to bus bit
45  * @param p9 DigitalOut pin to connect to bus bit
46  * @param p10 DigitalOut pin to connect to bus bit
47  * @param p11 DigitalOut pin to connect to bus bit
48  * @param p12 DigitalOut pin to connect to bus bit
49  * @param p13 DigitalOut pin to connect to bus bit
50  * @param p14 DigitalOut pin to connect to bus bit
51  * @param p15 DigitalOut pin to connect to bus bit
52  *
53  * @note Synchronization level: Thread safe
54  *
55  * @note
56  * It is only required to specify as many pin variables as is required
57  * for the bus; the rest will default to NC (not connected)
58  */
59  BusOut(PinName p0, PinName p1 = NC, PinName p2 = NC, PinName p3 = NC,
60  PinName p4 = NC, PinName p5 = NC, PinName p6 = NC, PinName p7 = NC,
61  PinName p8 = NC, PinName p9 = NC, PinName p10 = NC, PinName p11 = NC,
62  PinName p12 = NC, PinName p13 = NC, PinName p14 = NC, PinName p15 = NC);
63 
64  /** Create an BusOut, connected to the specified pins
65  *
66  * @param pins An array of pins to connect to bus the bit
67  */
68  BusOut(PinName pins[16]);
69 
70  virtual ~BusOut();
71 
72  /** Write the value to the output bus
73  *
74  * @param value An integer specifying a bit to write for every corresponding DigitalOut pin
75  */
76  void write(int value);
77 
78  /** Read the value currently output on the bus
79  *
80  * @returns
81  * An integer with each bit corresponding to associated DigitalOut pin setting
82  */
83  int read();
84 
85  /** Binary mask of bus pins connected to actual pins (not NC pins)
86  * If bus pin is in NC state make corresponding bit will be cleared (set to 0), else bit will be set to 1
87  *
88  * @returns
89  * Binary mask of connected pins
90  */
91  int mask()
92  {
93  // No lock needed since _nc_mask is not modified outside the constructor
94  return _nc_mask;
95  }
96 
97  /** A shorthand for write()
98  * \sa BusOut::write()
99  */
100  BusOut &operator= (int v);
101  BusOut &operator= (BusOut &rhs);
102 
103  /** Access to particular bit in random-iterator fashion
104  * @param index Bit Position
105  */
106  DigitalOut &operator[](int index);
107 
108  /** A shorthand for read()
109  * \sa BusOut::read()
110  */
111  operator int();
112 #if !defined(DOXYGEN_ONLY)
113 protected:
114  virtual void lock();
115  virtual void unlock();
116  DigitalOut *_pin[16];
117 
118  /* Mask of bus's NC pins
119  * If bit[n] is set to 1 - pin is connected
120  * if bit[n] is cleared - pin is not connected (NC)
121  */
122  int _nc_mask;
123 
124  PlatformMutex _mutex;
125 #endif
126 };
127 
128 } // namespace mbed
129 
130 #endif
BusOut(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)
Create an BusOut, connected to the specified pins.
DigitalOut & operator[](int index)
Access to particular bit in random-iterator fashion.
int mask()
Binary mask of bus pins connected to actual pins (not NC pins) If bus pin is in NC state make corresp...
Definition: BusOut.h:91
BusOut & operator=(int v)
A shorthand for write()
void write(int value)
Write the value to the output bus.
Prevents generation of copy constructor and copy assignment operator in derived classes.
Definition: NonCopyable.h:168
int read()
Read the value currently output on the bus.
The PlatformMutex class is used to synchronize the execution of threads.
Definition: PlatformMutex.h:47
A digital output, used for setting the state of a pin.
Definition: DigitalOut.h:47
A digital output bus, used for setting the state of a collection of pins.
Definition: BusOut.h:30
Definition: AnalogIn.h:28
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