TWI.h 4.62 KB
 Dean Camera committed Jan 19, 2010 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 /* LUFA Library Copyright (C) Dean Camera, 2010. dean [at] fourwalledcubicle [dot] com www.fourwalledcubicle.com */ /* Copyright 2010 Dean Camera (dean [at] fourwalledcubicle [dot] com) Permission to use, copy, modify, distribute, and sell this software and its documentation for any purpose is hereby granted without fee, provided that the above copyright notice appear in all copies and that both that the copyright notice and this permission notice and warranty disclaimer appear in supporting documentation, and that the name of the author not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission. The author disclaim all warranties with regard to this software, including all implied warranties of merchantability and fitness. In no event shall the author be liable for any special, indirect or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with the use or performance of this software. */ /** \file * * Master mode TWI driver for the AT90USB1287, AT90USB1286, AT90USB647, AT90USB646, ATMEGA16U4 and ATMEGA32U4 AVRs. * * \note This file should not be included directly. It is automatically included as needed by the TWI driver * dispatch header located in LUFA/Drivers/Peripheral/TWI.h. */ /** \ingroup Group_TWI * @defgroup Group_TWI_AVRU4U6U7 Series U4, U6 and U7 Model TWI Driver * * @{ */ #ifndef __TWI_AVRU4U6U7_H__ #define __TWI_AVRU4U6U7_H__ /* Includes: */ #include "../../../Common/Common.h" #include #include #include /* Enable C linkage for C++ Compilers: */ #if defined(__cplusplus) extern "C" { #endif /* Preprocessor Checks: */ #if !defined(INCLUDE_FROM_TWI_H) #error Do not include this file directly. Include LUFA/Drivers/Peripheral/TWI.h instead. #endif /* Public Interface - May be used in end-application: */ /* Pseudo-Function Macros: */ #if defined(__DOXYGEN__) /** Initializes the TWI hardware into master mode, ready for data transmission and reception. This must be * before any other TWI operations. */ static inline void TWI_Init(void); /** Turns off the TWI driver hardware. If this is called, any further TWI operations will require a call to * \ref TWI_Init() before the TWI can be used again. */ static inline void TWI_ShutDown(void); #else #define TWI_Init() MACROS{ TWCR |= (1 << TWEN); }MACROE #define TWI_ShutDown() MACROS{ TWCR &= ~(1 << TWEN); }MACROE #endif /* Inline Functions: */ /** Sends a TWI STOP onto the TWI bus, terminating communication with the currently addressed device. */ static inline void TWI_StopTransmission(void) { TWCR = ((1 << TWINT) | (1 << TWSTO) | (1 << TWEN)); } /** Sends a byte to the currently addressed device on the TWI bus. *  Dean Camera committed Jan 27, 2010 91  * \param[in] Byte Byte to send to the currently addressed device  Dean Camera committed Jan 19, 2010 92 93 94 95 96 97 98 99 100 101 102 103 104 105  * * \return Boolean true if the recipient ACKed the byte, false otherwise */ static inline bool TWI_SendByte(uint8_t Byte) { TWDR = Byte; TWCR = ((1 << TWINT) | (1 << TWEN)); while (!(TWCR & (1 << TWINT))); return ((TWSR & TW_STATUS_MASK) == TW_MT_DATA_ACK); } /** Receives a byte from the currently addressed device on the TWI bus. *  Dean Camera committed Jan 27, 2010 106 107  * \param[in] Byte Location where the read byte is to be stored * \param[in] LastByte Indicates if the byte should be ACKed if false, NAKed if true  Dean Camera committed Jan 19, 2010 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127  * * \return Boolean true if the byte reception sucessfully completed, false otherwise */ static inline bool TWI_ReceiveByte(uint8_t* Byte, bool LastByte) { uint8_t TWCRMask = ((1 << TWINT) | (1 << TWEN)); if (!(LastByte)) TWCRMask |= (1 << TWEA); TWCR = TWCRMask; while (!(TWCR & (1 << TWINT))); *Byte = TWDR; return ((TWSR & TW_STATUS_MASK) == TW_MR_DATA_ACK); } /* Function Prototypes: */ /** Begins a master mode TWI bus communication with the given slave device address. *  Dean Camera committed Jan 27, 2010 128  * \param[in] SlaveAddress Address of the slave TWI device to communicate with  Dean Camera committed Jan 19, 2010 129 130 131 132 133 134 135 136 137 138 139 140 141  * * \return Boolean true if the device is ready for data, false otherwise */ bool TWI_StartTransmission(uint8_t SlaveAddress); /* Disable C linkage for C++ Compilers: */ #if defined(__cplusplus) } #endif #endif /** @} */