TWI_AVR8.h 12.4 KB
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 Dean Camera committed May 08, 2010 1 2 /* LUFA Library  Dean Camera committed Jan 01, 2011 3  Copyright (C) Dean Camera, 2011.  4   Dean Camera committed May 08, 2010 5  dean [at] fourwalledcubicle [dot] com  Dean Camera committed Oct 28, 2010 6  www.lufa-lib.org  Dean Camera committed May 08, 2010 7 8 9 */ /*  Dean Camera committed Jan 01, 2011 10  Copyright 2011 Dean Camera (dean [at] fourwalledcubicle [dot] com)  Dean Camera committed May 08, 2010 11   12  Permission to use, copy, modify, distribute, and sell this  Dean Camera committed May 08, 2010 13  software and its documentation for any purpose is hereby granted  14  without fee, provided that the above copyright notice appear in  Dean Camera committed May 08, 2010 15  all copies and that both that the copyright notice and this  16 17 18  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  Dean Camera committed May 08, 2010 19 20 21 22 23 24 25 26 27 28 29 30 31  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  Dean Camera committed Feb 19, 2011 32  * \brief TWI Peripheral Driver (AVR8)  Dean Camera committed May 08, 2010 33  *  Dean Camera committed Feb 19, 2011 34  * On-chip TWI driver for the 8-bit AVR microcontrollers.  Dean Camera committed May 08, 2010 35 36 37 38 39 40  * * \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  Dean Camera committed Feb 19, 2011 41  * \defgroup Group_TWI_AVR8 TWI Peripheral Driver (AVR8)  Dean Camera committed May 08, 2010 42  *  Dean Camera committed Feb 19, 2011 43 44  * \section Sec_ModDescription Module Description * Master mode TWI driver for the 8-bit AVR microcontrollers which contain a hardware TWI module.  Dean Camera committed May 08, 2010 45 46 47 48  * * \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. *  Dean Camera committed Dec 26, 2010 49 50 51 52  * \section Sec_ExampleUsage Example Usage * The following snippet is an example of how this module may be used within a typical * application. *  Dean Camera committed Jan 13, 2011 53  * Low Level API Example:  Dean Camera committed Dec 26, 2010 54  * \code  Dean Camera committed Jun 01, 2011 55  * // Initialize the TWI driver before first use  Dean Camera committed Feb 26, 2011 56  * TWI_Init(TWI_BIT_PRESCALE_1, 10);  Dean Camera committed Dec 26, 2010 57  *  Dean Camera committed Jan 13, 2011 58  * // Start a write session to device at device address 0xA0, internal address 0xDC with a 10ms timeout  Dean Camera committed Dec 26, 2010 59 60  * if (TWI_StartTransmission(0xA0 | TWI_ADDRESS_WRITE, 10)) * {  Dean Camera committed Jan 13, 2011 61 62  * TWI_SendByte(0xDC); *  Dean Camera committed Dec 26, 2010 63 64 65 66 67 68 69 70  * TWI_SendByte(0x01); * TWI_SendByte(0x02); * TWI_SendByte(0x03); * * // Must stop transmission afterwards to release the bus * TWI_StopTransmission(); * } *  Dean Camera committed Jan 13, 2011 71 72  * // Start a read session to device at address 0xA0, internal address 0xDC with a 10ms timeout * if (TWI_StartTransmission(0xA0 | TWI_ADDRESS_WRITE, 10))  Dean Camera committed Dec 26, 2010 73  * {  Dean Camera committed Jan 13, 2011 74 75  * TWI_SendByte(0xDC); * TWI_StopTransmission();  Dean Camera committed Dec 26, 2010 76  *  Dean Camera committed Jan 13, 2011 77 78 79  * if (TWI_StartTransmission(0xA0 | TWI_ADDRESS_READ, 10)) * { * uint8_t Byte1, Byte2, Byte3;  Dean Camera committed Dec 26, 2010 80  *  Dean Camera committed Jan 13, 2011 81 82 83 84 85 86 87 88  * // Read three bytes, acknowledge after the third byte is received * TWI_ReceiveByte(&Byte1, false); * TWI_ReceiveByte(&Byte2, false); * TWI_ReceiveByte(&Byte3, true); * * // Must stop transmission afterwards to release the bus * TWI_StopTransmission(); * }  Dean Camera committed Dec 26, 2010 89 90 91  * } * \endcode *  Dean Camera committed Jan 13, 2011 92 93  * High Level API Example: * \code  Dean Camera committed Jun 01, 2011 94  * // Initialize the TWI driver before first use  Dean Camera committed Feb 26, 2011 95  * TWI_Init(TWI_BIT_PRESCALE_1, 10);  Dean Camera committed Jan 13, 2011 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111  * * // Start a write session to device at device address 0xA0, internal address 0xDC with a 10ms timeout * uint8_t InternalWriteAddress = 0xDC; * uint8_t WritePacket[3] = {0x01, 0x02, 0x03}; * * TWI_WritePacket(0xA0, 10, &InternalWriteAddress, sizeof(InternalWriteAddress), * &WritePacket, sizeof(WritePacket); * * // Start a read session to device at address 0xA0, internal address 0xDC with a 10ms timeout * uint8_t InternalReadAddress = 0xDC; * uint8_t ReadPacket[3]; * * TWI_ReadPacket(0xA0, 10, &InternalReadAddress, sizeof(InternalReadAddress), * &ReadPacket, sizeof(ReadPacket); * \endcode *  Dean Camera committed May 08, 2010 112 113 114  * @{ */  Dean Camera committed Feb 19, 2011 115 116 #ifndef __TWI_AVR8_H__ #define __TWI_AVR8_H__  Dean Camera committed May 08, 2010 117 118 119  /* Includes: */ #include "../../../Common/Common.h"  120   Dean Camera committed Jan 13, 2011 121  #include  Dean Camera committed May 08, 2010 122  #include  123   Dean Camera committed May 08, 2010 124 125 126 127 128 129  /* Enable C linkage for C++ Compilers: */ #if defined(__cplusplus) extern "C" { #endif /* Preprocessor Checks: */  Dean Camera committed Feb 19, 2011 130  #if !defined(__INCLUDE_FROM_TWI_H) && !defined(__INCLUDE_FROM_TWI_C)  Dean Camera committed May 08, 2010 131 132 133  #error Do not include this file directly. Include LUFA/Drivers/Peripheral/TWI.h instead. #endif  Dean Camera committed Feb 19, 2011 134 135 136 137 138 139 140  #if !(defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB646__) || \ defined(__AVR_AT90USB1287__) || defined(__AVR_AT90USB647__) || \ defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__) || \ defined(__AVR_ATmega32U6__)) #error The TWI peripheral driver is not currently available for your selected microcontroller model. #endif  Dean Camera committed May 08, 2010 141  /* Public Interface - May be used in end-application: */  Dean Camera committed Dec 26, 2010 142 143 144 145  /* Macros: */ /** TWI slave device address mask for a read session. Mask with a slave device base address to obtain * the correct TWI bus address for the slave device when reading data from it. */  Dean Camera committed Jan 13, 2011 146  #define TWI_ADDRESS_READ 0x00  Dean Camera committed Dec 26, 2010 147 148 149 150  /** TWI slave device address mask for a write session. Mask with a slave device base address to obtain * the correct TWI bus address for the slave device when writing data to it. */  Dean Camera committed Jan 13, 2011 151 152 153 154 155 156 157  #define TWI_ADDRESS_WRITE 0x01 /** Mask to retrieve the base address for a TWI device, which can then be ORed with \ref TWI_ADDRESS_READ * or \ref TWI_ADDRESS_WRITE to obtain the device's read and write address respectively. */ #define TWI_DEVICE_ADDRESS_MASK 0xFE  Dean Camera committed Feb 26, 2011 158 159 160 161 162 163 164 165 166 167 168 169  /** Bit length prescaler for \ref TWI_Init(). This mask multiplies the TWI bit length prescaler by 1. */ #define TWI_BIT_PRESCALE_1 ((0 << TWPS1) | (0 << TWPS0)) /** Bit length prescaler for \ref TWI_Init(). This mask multiplies the TWI bit length prescaler by 4. */ #define TWI_BIT_PRESCALE_4 ((0 << TWPS1) | (1 << TWPS0)) /** Bit length prescaler for \ref TWI_Init(). This mask multiplies the TWI bit length prescaler by 16. */ #define TWI_BIT_PRESCALE_16 ((1 << TWPS1) | (0 << TWPS0)) /** Bit length prescaler for \ref TWI_Init(). This mask multiplies the TWI bit length prescaler by 64. */ #define TWI_BIT_PRESCALE_64 ((1 << TWPS1) | (1 << TWPS0))  Dean Camera committed Jan 13, 2011 170 171 172 173  /* Enums: */ /** Enum for the possible return codes of the TWI transfer start routine and other dependant TWI functions. */ enum TWI_ErrorCodes_t {  Dean Camera committed Jun 01, 2011 174  TWI_ERROR_NoError = 0, /**< Indicates that the command completed successfully. */  Dean Camera committed Jan 13, 2011 175 176 177 178 179 180  TWI_ERROR_BusFault = 1, /**< A TWI bus fault occurred while attempting to capture the bus. */ TWI_ERROR_BusCaptureTimeout = 2, /**< A timeout occurred whilst waiting for the bus to be ready. */ TWI_ERROR_SlaveResponseTimeout = 3, /**< No ACK received at the nominated slave address within the timeout period. */ TWI_ERROR_SlaveNotReady = 4, /**< Slave NAKed the TWI bus START condition. */ TWI_ERROR_SlaveNAK = 5, /**< Slave NAKed whilst attempting to send data to the device. */ };  Dean Camera committed Dec 26, 2010 181   Dean Camera committed May 08, 2010 182  /* Inline Functions: */  Dean Camera committed Jun 01, 2011 183  /** Initializes the TWI hardware into master mode, ready for data transmission and reception. This must be  Dean Camera committed Jul 22, 2010 184  * before any other TWI operations.  Dean Camera committed Feb 26, 2011 185 186 187 188 189 190 191 192  * * The generated SCL frequency will be according to the formula
F_CPU / (16 + 2 * BitLength + 4 ^ Prescale)
. * * \note The value of the \c BitLength parameter should not be set below 10 or invalid bus conditions may * occur, as indicated in the AVR8 microcontroller datasheet. * * \param[in] Prescale Prescaler to use when determining the bus frequency, a \c TWI_BIT_PRESCALE_* value. * \param[in] BitLength Length of the bits sent on the bus.  Dean Camera committed Jul 22, 2010 193  */  Dean Camera committed Feb 26, 2011 194 195  static inline void TWI_Init(const uint8_t Prescale, const uint8_t BitLength) ATTR_ALWAYS_INLINE; static inline void TWI_Init(const uint8_t Prescale, const uint8_t BitLength)  Dean Camera committed Jul 22, 2010 196  {  Dean Camera committed Feb 26, 2011 197 198 199  TWCR |= (1 << TWEN); TWSR = Prescale; TWBR = BitLength;  Dean Camera committed Jul 22, 2010 200  }  201   Dean Camera committed Jul 22, 2010 202 203  /** 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.  204  */  205 206  static inline void TWI_Disable(void) ATTR_ALWAYS_INLINE; static inline void TWI_Disable(void)  Dean Camera committed Jul 22, 2010 207 208 209 210  { TWCR &= ~(1 << TWEN); }  Dean Camera committed May 08, 2010 211  /** Sends a TWI STOP onto the TWI bus, terminating communication with the currently addressed device. */  Dean Camera committed Jul 22, 2010 212  static inline void TWI_StopTransmission(void) ATTR_ALWAYS_INLINE;  Dean Camera committed May 08, 2010 213 214 215 216 217 218 219 220 221  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. * * \param[in] Byte Byte to send to the currently addressed device *  Dean Camera committed Jan 08, 2011 222  * \return Boolean \c true if the recipient ACKed the byte, \c false otherwise  Dean Camera committed May 08, 2010 223  */  Dean Camera committed Jul 21, 2010 224  static inline bool TWI_SendByte(const uint8_t Byte)  Dean Camera committed May 08, 2010 225 226  { TWDR = Byte;  227  TWCR = ((1 << TWINT) | (1 << TWEN));  Dean Camera committed May 08, 2010 228 229 230 231 232 233 234  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 May 29, 2010 235  * \param[in] Byte Location where the read byte is to be stored  Dean Camera committed May 08, 2010 236 237  * \param[in] LastByte Indicates if the byte should be ACKed if false, NAKed if true *  Dean Camera committed Jan 08, 2011 238  * \return Boolean \c true if the byte reception successfully completed, \c false otherwise  Dean Camera committed May 08, 2010 239  */  Dean Camera committed Jan 13, 2011 240 241  static inline uint8_t TWI_ReceiveByte(uint8_t* const Byte, const bool LastByte)  Dean Camera committed May 08, 2010 242 243  { uint8_t TWCRMask = ((1 << TWINT) | (1 << TWEN));  244   Dean Camera committed May 08, 2010 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260  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. * * \param[in] SlaveAddress Address of the slave TWI device to communicate with * \param[in] TimeoutMS Timeout period within which the slave must respond, in milliseconds *  Dean Camera committed Jan 13, 2011 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291  * \return A value from the \ref TWI_ErrorCodes_t enum */ uint8_t TWI_StartTransmission(const uint8_t SlaveAddress, const uint8_t TimeoutMS); /** High level function to perform a complete packet transfer over the TWI bus to the specified * device. * * \param[in] SlaveAddress Base address of the TWI slave device to communicate with * \param[in] TimeoutMS Timeout for bus capture and slave START ACK, in milliseconds * \param[in] InternalAddress Pointer to a location where the internal slave read start address is stored * \param[in] InternalAddressLen Size of the internal device address, in bytes * \param[in] Buffer Pointer to a buffer where the read packet data is to be stored * \param[in] Length Size of the packet to read, in bytes */ uint8_t TWI_ReadPacket(const uint8_t SlaveAddress, const uint8_t TimeoutMS, const uint8_t* InternalAddress, uint8_t InternalAddressLen, uint8_t* Buffer, uint8_t Length); /** High level function to perform a complete packet transfer over the TWI bus from the specified * device. * * \param[in] SlaveAddress Base address of the TWI slave device to communicate with * \param[in] TimeoutMS Timeout for bus capture and slave START ACK, in milliseconds * \param[in] InternalAddress Pointer to a location where the internal slave write start address is stored * \param[in] InternalAddressLen Size of the internal device address, in bytes * \param[in] Buffer Pointer to a buffer where the packet data to send is stored * \param[in] Length Size of the packet to send, in bytes  Dean Camera committed May 08, 2010 292  */  Dean Camera committed Jan 13, 2011 293 294 295 296 297 298  uint8_t TWI_WritePacket(const uint8_t SlaveAddress, const uint8_t TimeoutMS, const uint8_t* InternalAddress, uint8_t InternalAddressLen, const uint8_t* Buffer, uint8_t Length);  Dean Camera committed May 08, 2010 299 300 301 302 303 304 305 306 307  /* Disable C linkage for C++ Compilers: */ #if defined(__cplusplus) } #endif #endif /** @} */  308