From: mmaroti <mmaroti>
Date: Mon, 9 Mar 2009 17:54:23 +0000 (+0000)
Subject: make the FastSpiByte interface generic and implement it in Atm128Spi
X-Git-Tag: rc_6_tinyos_2_1_1~470
X-Git-Url: https://oss.titaniummirror.com/gitweb/?p=tinyos-2.x.git;a=commitdiff_plain;h=857a829a9dd7830efbf85b39aae30698c1059adb

make the FastSpiByte interface generic and implement it in Atm128Spi
---

diff --git a/tos/interfaces/FastSpiByte.nc b/tos/interfaces/FastSpiByte.nc
new file mode 100644
index 00000000..42ef4ea4
--- /dev/null
+++ b/tos/interfaces/FastSpiByte.nc
@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2007, Vanderbilt University
+ * All rights reserved.
+ *
+ * Permission to use, copy, modify, and distribute this software and its
+ * documentation for any purpose, without fee, and without written agreement is
+ * hereby granted, provided that the above copyright notice, the following
+ * two paragraphs and the author appear in all copies of this software.
+ * 
+ * IN NO EVENT SHALL THE VANDERBILT UNIVERSITY BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT
+ * OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE VANDERBILT
+ * UNIVERSITY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * 
+ * THE VANDERBILT UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE VANDERBILT UNIVERSITY HAS NO OBLIGATION TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ *
+ * 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
+ *
+ *	call FastSpiByte.spiSplitWrite(data[0]); // start the first byte
+ *	for(i = 1; i < length; ++i) {
+ *	   // finish the previous one and write the next one
+ *	  call FastSpiByte.spiSplitReadWrite(data[i]);
+ *	}
+ *	call FastSpiByte.spiSlitRead(); // finish the last byte
+ *
+ * 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);
+}