siva surendar / mbed-dev

mbed library sources. Supersedes mbed-src.

Fork of mbed-dev by mbed official

drivers/SPISlave.h@150:da61ba4e9755, 2016-11-25 (annotated)

Committer:
sivasuren
Date:
Fri Nov 25 07:57:40 2016 +0000
Revision:
150:da61ba4e9755
Parent:
149:156823d33999 
surendar changes

Who changed what in which revision?

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<> 149:156823d33999 1 /* mbed Microcontroller Library
<> 149:156823d33999 2 * Copyright (c) 2006-2013 ARM Limited
<> 149:156823d33999 3 *
<> 149:156823d33999 4 * Licensed under the Apache License, Version 2.0 (the "License");
<> 149:156823d33999 5 * you may not use this file except in compliance with the License.
<> 149:156823d33999 6 * You may obtain a copy of the License at
<> 149:156823d33999 7 *
<> 149:156823d33999 8 * http://www.apache.org/licenses/LICENSE-2.0
<> 149:156823d33999 9 *
<> 149:156823d33999 10 * Unless required by applicable law or agreed to in writing, software
<> 149:156823d33999 11 * distributed under the License is distributed on an "AS IS" BASIS,
<> 149:156823d33999 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
<> 149:156823d33999 13 * See the License for the specific language governing permissions and
<> 149:156823d33999 14 * limitations under the License.
<> 149:156823d33999 15 */
<> 149:156823d33999 16 #ifndef MBED_SPISLAVE_H
<> 149:156823d33999 17 #define MBED_SPISLAVE_H
<> 149:156823d33999 18
<> 149:156823d33999 19 #include "platform/platform.h"
<> 149:156823d33999 20
<> 149:156823d33999 21 #if DEVICE_SPISLAVE
<> 149:156823d33999 22
<> 149:156823d33999 23 #include "hal/spi_api.h"
<> 149:156823d33999 24
<> 149:156823d33999 25 namespace mbed {
<> 149:156823d33999 26 /** \addtogroup drivers */
<> 149:156823d33999 27 /** @{*/
<> 149:156823d33999 28
<> 149:156823d33999 29 /** A SPI slave, used for communicating with a SPI Master device
<> 149:156823d33999 30 *
<> 149:156823d33999 31 * The default format is set to 8-bits, mode 0, and a clock frequency of 1MHz
<> 149:156823d33999 32 *
<> 149:156823d33999 33 * @Note Synchronization level: Not protected
<> 149:156823d33999 34 *
<> 149:156823d33999 35 * Example:
<> 149:156823d33999 36 * @code
<> 149:156823d33999 37 * // Reply to a SPI master as slave
<> 149:156823d33999 38 *
<> 149:156823d33999 39 * #include "mbed.h"
<> 149:156823d33999 40 *
<> 149:156823d33999 41 * SPISlave device(p5, p6, p7, p8); // mosi, miso, sclk, ssel
<> 149:156823d33999 42 *
<> 149:156823d33999 43 * int main() {
<> 149:156823d33999 44 * device.reply(0x00); // Prime SPI with first reply
<> 149:156823d33999 45 * while(1) {
<> 149:156823d33999 46 * if(device.receive()) {
<> 149:156823d33999 47 * int v = device.read(); // Read byte from master
<> 149:156823d33999 48 * v = (v + 1) % 0x100; // Add one to it, modulo 256
<> 149:156823d33999 49 * device.reply(v); // Make this the next reply
<> 149:156823d33999 50 * }
<> 149:156823d33999 51 * }
<> 149:156823d33999 52 * }
<> 149:156823d33999 53 * @endcode
<> 149:156823d33999 54 */
<> 149:156823d33999 55 class SPISlave {
<> 149:156823d33999 56
<> 149:156823d33999 57 public:
<> 149:156823d33999 58
<> 149:156823d33999 59 /** Create a SPI slave connected to the specified pins
<> 149:156823d33999 60 *
<> 149:156823d33999 61 * mosi or miso can be specfied as NC if not used
<> 149:156823d33999 62 *
<> 149:156823d33999 63 * @param mosi SPI Master Out, Slave In pin
<> 149:156823d33999 64 * @param miso SPI Master In, Slave Out pin
<> 149:156823d33999 65 * @param sclk SPI Clock pin
<> 149:156823d33999 66 * @param ssel SPI chip select pin
<> 149:156823d33999 67 */
<> 149:156823d33999 68 SPISlave(PinName mosi, PinName miso, PinName sclk, PinName ssel);
<> 149:156823d33999 69
<> 149:156823d33999 70 /** Configure the data transmission format
<> 149:156823d33999 71 *
<> 149:156823d33999 72 * @param bits Number of bits per SPI frame (4 - 16)
<> 149:156823d33999 73 * @param mode Clock polarity and phase mode (0 - 3)
<> 149:156823d33999 74 *
<> 149:156823d33999 75 * @code
<> 149:156823d33999 76 * mode | POL PHA
<> 149:156823d33999 77 * -----+--------
<> 149:156823d33999 78 * 0 | 0 0
<> 149:156823d33999 79 * 1 | 0 1
<> 149:156823d33999 80 * 2 | 1 0
<> 149:156823d33999 81 * 3 | 1 1
<> 149:156823d33999 82 * @endcode
<> 149:156823d33999 83 */
<> 149:156823d33999 84 void format(int bits, int mode = 0);
<> 149:156823d33999 85
<> 149:156823d33999 86 /** Set the spi bus clock frequency
<> 149:156823d33999 87 *
<> 149:156823d33999 88 * @param hz SCLK frequency in hz (default = 1MHz)
<> 149:156823d33999 89 */
<> 149:156823d33999 90 void frequency(int hz = 1000000);
<> 149:156823d33999 91
<> 149:156823d33999 92 /** Polls the SPI to see if data has been received
<> 149:156823d33999 93 *
<> 149:156823d33999 94 * @returns
<> 149:156823d33999 95 * 0 if no data,
<> 149:156823d33999 96 * 1 otherwise
<> 149:156823d33999 97 */
<> 149:156823d33999 98 int receive(void);
<> 149:156823d33999 99
<> 149:156823d33999 100 /** Retrieve data from receive buffer as slave
<> 149:156823d33999 101 *
<> 149:156823d33999 102 * @returns
<> 149:156823d33999 103 * the data in the receive buffer
<> 149:156823d33999 104 */
<> 149:156823d33999 105 int read(void);
<> 149:156823d33999 106
<> 149:156823d33999 107 /** Fill the transmission buffer with the value to be written out
<> 149:156823d33999 108 * as slave on the next received message from the master.
<> 149:156823d33999 109 *
<> 149:156823d33999 110 * @param value the data to be transmitted next
<> 149:156823d33999 111 */
<> 149:156823d33999 112 void reply(int value);
<> 149:156823d33999 113
<> 149:156823d33999 114 protected:
<> 149:156823d33999 115 spi_t _spi;
<> 149:156823d33999 116
<> 149:156823d33999 117 int _bits;
<> 149:156823d33999 118 int _mode;
<> 149:156823d33999 119 int _hz;
<> 149:156823d33999 120 };
<> 149:156823d33999 121
<> 149:156823d33999 122 } // namespace mbed
<> 149:156823d33999 123
<> 149:156823d33999 124 #endif
<> 149:156823d33999 125
<> 149:156823d33999 126 #endif
<> 149:156823d33999 127
<> 149:156823d33999 128 /** @}*/