Diff: cpp/SPISlave.h

Revision:

0:fd0d7bdfcdc2

Child:

2:143cac498751

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cpp/SPISlave.h	Tue Nov 20 17:24:08 2012 +0000
@@ -0,0 +1,132 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2012 ARM Limited
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#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