sinyuu masahito / Mbed 2 deprecated yozakura_arm

Arm control program for Yozakura

Dependencies:   mbed

SerialHalfDuplex/SerialHalfDuplex.cpp@0:6b3497b2f2ec, 2015-04-24 (annotated)

Committer:
masasin
Date:
Fri Apr 24 01:55:32 2015 +0000
Revision:
0:6b3497b2f2ec
Initial commit

Who changed what in which revision?

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masasin 0:6b3497b2f2ec 1 /* mbed Microcontroller Library
masasin 0:6b3497b2f2ec 2 * Copyright (c) 2006-2012 ARM Limited
masasin 0:6b3497b2f2ec 3 *
masasin 0:6b3497b2f2ec 4 * Permission is hereby granted, free of charge, to any person obtaining a copy
masasin 0:6b3497b2f2ec 5 * of this software and associated documentation files (the "Software"), to deal
masasin 0:6b3497b2f2ec 6 * in the Software without restriction, including without limitation the rights
masasin 0:6b3497b2f2ec 7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
masasin 0:6b3497b2f2ec 8 * copies of the Software, and to permit persons to whom the Software is
masasin 0:6b3497b2f2ec 9 * furnished to do so, subject to the following conditions:
masasin 0:6b3497b2f2ec 10 *
masasin 0:6b3497b2f2ec 11 * The above copyright notice and this permission notice shall be included in
masasin 0:6b3497b2f2ec 12 * all copies or substantial portions of the Software.
masasin 0:6b3497b2f2ec 13 *
masasin 0:6b3497b2f2ec 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
masasin 0:6b3497b2f2ec 15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
masasin 0:6b3497b2f2ec 16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
masasin 0:6b3497b2f2ec 17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
masasin 0:6b3497b2f2ec 18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
masasin 0:6b3497b2f2ec 19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
masasin 0:6b3497b2f2ec 20 * SOFTWARE.
masasin 0:6b3497b2f2ec 21 *
masasin 0:6b3497b2f2ec 22 * NOTE: This is an unsupported legacy untested library.
masasin 0:6b3497b2f2ec 23 */
masasin 0:6b3497b2f2ec 24 #include "SerialHalfDuplex.h"
masasin 0:6b3497b2f2ec 25
masasin 0:6b3497b2f2ec 26 #if DEVICE_SERIAL
masasin 0:6b3497b2f2ec 27
masasin 0:6b3497b2f2ec 28 #include "pinmap.h"
masasin 0:6b3497b2f2ec 29 #include "serial_api.h"
masasin 0:6b3497b2f2ec 30 #include "gpio_api.h"
masasin 0:6b3497b2f2ec 31 //#include "RawSerial.h"
masasin 0:6b3497b2f2ec 32
masasin 0:6b3497b2f2ec 33 namespace mbed {
masasin 0:6b3497b2f2ec 34
masasin 0:6b3497b2f2ec 35 SerialHalfDuplex::SerialHalfDuplex(PinName tx, PinName rx, const char *name)
masasin 0:6b3497b2f2ec 36 : Serial(tx, rx, name) {
masasin 0:6b3497b2f2ec 37 _txpin = tx;
masasin 0:6b3497b2f2ec 38
masasin 0:6b3497b2f2ec 39 // set as input
masasin 0:6b3497b2f2ec 40 gpio_set(_txpin);
masasin 0:6b3497b2f2ec 41 pin_mode(_txpin, PullNone); // no pull
masasin 0:6b3497b2f2ec 42 pin_function(_txpin, 0); // set as gpio
masasin 0:6b3497b2f2ec 43 }
masasin 0:6b3497b2f2ec 44
masasin 0:6b3497b2f2ec 45 // To transmit a byte in half duplex mode:
masasin 0:6b3497b2f2ec 46 // 1. Disable interrupts, so we don't trigger on loopback byte
masasin 0:6b3497b2f2ec 47 // 2. Set tx pin to UART out
masasin 0:6b3497b2f2ec 48 // 3. Transmit byte as normal
masasin 0:6b3497b2f2ec 49 // 4. Read back byte from looped back tx pin - this both confirms that the
masasin 0:6b3497b2f2ec 50 // transmit has occurred, and also clears the byte from the buffer.
masasin 0:6b3497b2f2ec 51 // 5. Return pin to input mode
masasin 0:6b3497b2f2ec 52 // 6. Re-enable interrupts
masasin 0:6b3497b2f2ec 53
masasin 0:6b3497b2f2ec 54 int SerialHalfDuplex::_putc(int c) {
masasin 0:6b3497b2f2ec 55 int retc;
masasin 0:6b3497b2f2ec 56
masasin 0:6b3497b2f2ec 57 // TODO: We should not disable all interrupts
masasin 0:6b3497b2f2ec 58 __disable_irq();
masasin 0:6b3497b2f2ec 59
masasin 0:6b3497b2f2ec 60 serial_pinout_tx(_txpin);
masasin 0:6b3497b2f2ec 61
masasin 0:6b3497b2f2ec 62 Serial::_putc(c);
masasin 0:6b3497b2f2ec 63 retc = Serial::getc(); // reading also clears any interrupt
masasin 0:6b3497b2f2ec 64
masasin 0:6b3497b2f2ec 65 pin_function(_txpin, 0);
masasin 0:6b3497b2f2ec 66
masasin 0:6b3497b2f2ec 67 __enable_irq();
masasin 0:6b3497b2f2ec 68
masasin 0:6b3497b2f2ec 69 return retc;
masasin 0:6b3497b2f2ec 70 }
masasin 0:6b3497b2f2ec 71
masasin 0:6b3497b2f2ec 72 int SerialHalfDuplex::_getc(void) {
masasin 0:6b3497b2f2ec 73 return Serial::_getc();
masasin 0:6b3497b2f2ec 74 }
masasin 0:6b3497b2f2ec 75
masasin 0:6b3497b2f2ec 76 } // End namespace
masasin 0:6b3497b2f2ec 77
masasin 0:6b3497b2f2ec 78 #endif