mbed library sources
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api/SPISlave.h
- Committer:
- todotani
- Date:
- 2014-09-05
- Revision:
- 308:59cc78a25982
- Parent:
- 13:0645d8841f51
File content as of revision 308:59cc78a25982:
/* mbed Microcontroller Library * Copyright (c) 2006-2013 ARM Limited * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef MBED_SPISLAVE_H #define MBED_SPISLAVE_H #include "platform.h" #if DEVICE_SPISLAVE #include "spi_api.h" namespace mbed { /** A SPI slave, used for communicating with a SPI Master device * * The default format is set to 8-bits, mode 0, and a clock frequency of 1MHz * * Example: * @code * // Reply to a SPI master as slave * * #include "mbed.h" * * SPISlave device(p5, p6, p7, p8); // mosi, miso, sclk, ssel * * int main() { * device.reply(0x00); // Prime SPI with first reply * while(1) { * if(device.receive()) { * int v = device.read(); // Read byte from master * v = (v + 1) % 0x100; // Add one to it, modulo 256 * device.reply(v); // Make this the next reply * } * } * } * @endcode */ class SPISlave { public: /** Create a SPI slave connected to the specified pins * * Pin Options: * (5, 6, 7i, 8) or (11, 12, 13, 14) * * mosi or miso can be specfied as NC if not used * * @param mosi SPI Master Out, Slave In pin * @param miso SPI Master In, Slave Out pin * @param sclk SPI Clock pin * @param ssel SPI chip select pin * @param name (optional) A string to identify the object */ SPISlave(PinName mosi, PinName miso, PinName sclk, PinName ssel); /** Configure the data transmission format * * @param bits Number of bits per SPI frame (4 - 16) * @param mode Clock polarity and phase mode (0 - 3) * * @code * mode | POL PHA * -----+-------- * 0 | 0 0 * 1 | 0 1 * 2 | 1 0 * 3 | 1 1 * @endcode */ void format(int bits, int mode = 0); /** Set the spi bus clock frequency * * @param hz SCLK frequency in hz (default = 1MHz) */ void frequency(int hz = 1000000); /** Polls the SPI to see if data has been received * * @returns * 0 if no data, * 1 otherwise */ int receive(void); /** Retrieve data from receive buffer as slave * * @returns * the data in the receive buffer */ int read(void); /** Fill the transmission buffer with the value to be written out * as slave on the next received message from the master. * * @param value the data to be transmitted next */ void reply(int value); protected: spi_t _spi; int _bits; int _mode; int _hz; }; } // namespace mbed #endif #endif