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/*
* Copyright (c) 2007, Vanderbilt University
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the
* distribution.
* - Neither the name of the copyright holder nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Author: Miklos Maroti
*/
/**
* This is a natural extension of the SpiByte interface which allows fast
* data transfers comparable to the SpiStream interface. You may want to
* use the following code sequence to write a buffer as fast as possible
*
* uint8_t *data;
* uint8_t *response;
*
* // start the first byte
* call FastSpiByte.splitWrite(data[0]);
* for(i = 1; i < length; ++i) {
* // finish the previous one and write the next one
* response[i-1] = call FastSpiByte.splitReadWrite(data[i]);
* }
* // finish the last byte
* response[length-1] = call FastSpiByte.splitRead();
*
* You can also do some useful computation (like calculate a CRC) while the
* hardware is sending the byte.
*/
interface FastSpiByte
{
/**
* Starts a split-phase SPI data transfer with the given data.
* A splitRead/splitReadWrite command must follow this command even
* if the result is unimportant.
*/
async command void splitWrite(uint8_t data);
/**
* Finishes the split-phase SPI data transfer by waiting till
* the write command comletes and returning the received data.
*/
async command uint8_t splitRead();
/**
* This command first reads the SPI register and then writes
* there the new data, then returns.
*/
async command uint8_t splitReadWrite(uint8_t data);
/**
* This is the standard SpiByte.write command but a little
* faster as we should not need to adjust the power state there.
* (To be consistent, this command could have be named splitWriteRead).
*/
async command uint8_t write(uint8_t data);
}
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