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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 /**
26  * \defgroup drivers_BusOut BusOut class
27  * \ingroup drivers-public-api-gpio
28  * @{
29  */
30 
31 /** A digital output bus, used for setting the state of a collection of pins
32  */
33 class BusOut : private NonCopyable<BusOut> {
34 
35 public:
36 
37  /** Create an BusOut, connected to the specified pins
38  *
39  * @param p0 DigitalOut pin to connect to bus bit
40  * @param p1 DigitalOut pin to connect to bus bit
41  * @param p2 DigitalOut pin to connect to bus bit
42  * @param p3 DigitalOut pin to connect to bus bit
43  * @param p4 DigitalOut pin to connect to bus bit
44  * @param p5 DigitalOut pin to connect to bus bit
45  * @param p6 DigitalOut pin to connect to bus bit
46  * @param p7 DigitalOut pin to connect to bus bit
47  * @param p8 DigitalOut pin to connect to bus bit
48  * @param p9 DigitalOut pin to connect to bus bit
49  * @param p10 DigitalOut pin to connect to bus bit
50  * @param p11 DigitalOut pin to connect to bus bit
51  * @param p12 DigitalOut pin to connect to bus bit
52  * @param p13 DigitalOut pin to connect to bus bit
53  * @param p14 DigitalOut pin to connect to bus bit
54  * @param p15 DigitalOut pin to connect to bus bit
55  *
56  * @note Synchronization level: Thread safe
57  *
58  * @note
59  * It is only required to specify as many pin variables as is required
60  * for the bus; the rest will default to NC (not connected)
61  */
62  BusOut(PinName p0, PinName p1 = NC, PinName p2 = NC, PinName p3 = NC,
63  PinName p4 = NC, PinName p5 = NC, PinName p6 = NC, PinName p7 = NC,
64  PinName p8 = NC, PinName p9 = NC, PinName p10 = NC, PinName p11 = NC,
65  PinName p12 = NC, PinName p13 = NC, PinName p14 = NC, PinName p15 = NC);
66 
67  /** Create an BusOut, connected to the specified pins
68  *
69  * @param pins An array of pins to connect to bus the bit
70  */
71  BusOut(PinName pins[16]);
72 
73  virtual ~BusOut();
74 
75  /** Write the value to the output bus
76  *
77  * @param value An integer specifying a bit to write for every corresponding DigitalOut pin
78  */
79  void write(int value);
80 
81  /** Read the value currently output on the bus
82  *
83  * @returns
84  * An integer with each bit corresponding to associated DigitalOut pin setting
85  */
86  int read();
87 
88  /** Binary mask of bus pins connected to actual pins (not NC pins)
89  * If bus pin is in NC state make corresponding bit will be cleared (set to 0), else bit will be set to 1
90  *
91  * @returns
92  * Binary mask of connected pins
93  */
94  int mask()
95  {
96  // No lock needed since _nc_mask is not modified outside the constructor
97  return _nc_mask;
98  }
99 
100  /** A shorthand for write()
101  * \sa BusOut::write()
102  */
103  BusOut &operator= (int v);
104  BusOut &operator= (BusOut &rhs);
105 
106  /** Access to particular bit in random-iterator fashion
107  * @param index Bit Position
108  */
109  DigitalOut &operator[](int index);
110 
111  /** A shorthand for read()
112  * \sa BusOut::read()
113  */
114  operator int();
115 #if !defined(DOXYGEN_ONLY)
116 protected:
117  virtual void lock();
118  virtual void unlock();
119  DigitalOut *_pin[16];
120 
121  /* Mask of bus's NC pins
122  * If bit[n] is set to 1 - pin is connected
123  * if bit[n] is cleared - pin is not connected (NC)
124  */
125  int _nc_mask;
126 
127  PlatformMutex _mutex;
128 #endif
129 };
130 
131 /** @}*/
132 
133 } // namespace mbed
134 
135 #endif
mbed::BusOut::BusOut
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.
mbed::BusOut::operator[]
DigitalOut & operator[](int index)
Access to particular bit in random-iterator fashion.
mbed::BusOut::mask
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:94
mbed::BusOut::operator=
BusOut & operator=(int v)
A shorthand for write()
mbed::BusOut::write
void write(int value)
Write the value to the output bus.
mbed::NonCopyable
Prevents generation of copy constructor and copy assignment operator in derived classes.
Definition: NonCopyable.h:169
mbed::BusOut::read
int read()
Read the value currently output on the bus.
PlatformMutex
The PlatformMutex class is used to synchronize the execution of threads.
Definition: PlatformMutex.h:47
mbed::DigitalOut
A digital output, used for setting the state of a pin.
Definition: DigitalOut.h:49
mbed::BusOut
A digital output bus, used for setting the state of a collection of pins.
Definition: BusOut.h:33
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