3 Copyright (C) Dean Camera, 2012.
\r
5 dean [at] fourwalledcubicle [dot] com
\r
10 Copyright 2012 Dean Camera (dean [at] fourwalledcubicle [dot] com)
\r
12 Permission to use, copy, modify, distribute, and sell this
\r
13 software and its documentation for any purpose is hereby granted
\r
14 without fee, provided that the above copyright notice appear in
\r
15 all copies and that both that the copyright notice and this
\r
16 permission notice and warranty disclaimer appear in supporting
\r
17 documentation, and that the name of the author not be used in
\r
18 advertising or publicity pertaining to distribution of the
\r
19 software without specific, written prior permission.
\r
21 The author disclaim all warranties with regard to this
\r
22 software, including all implied warranties of merchantability
\r
23 and fitness. In no event shall the author be liable for any
\r
24 special, indirect or consequential damages or any damages
\r
25 whatsoever resulting from loss of use, data or profits, whether
\r
26 in an action of contract, negligence or other tortious action,
\r
27 arising out of or in connection with the use or performance of
\r
32 * \brief TWI Peripheral Driver (AVR8)
\r
34 * On-chip TWI driver for the 8-bit AVR microcontrollers.
\r
36 * \note This file should not be included directly. It is automatically included as needed by the TWI driver
\r
37 * dispatch header located in LUFA/Drivers/Peripheral/TWI.h.
\r
40 /** \ingroup Group_TWI
\r
41 * \defgroup Group_TWI_AVR8 TWI Peripheral Driver (AVR8)
\r
43 * \section Sec_ModDescription Module Description
\r
44 * Master mode TWI driver for the 8-bit AVR microcontrollers which contain a hardware TWI module.
\r
46 * \note This file should not be included directly. It is automatically included as needed by the TWI driver
\r
47 * dispatch header located in LUFA/Drivers/Peripheral/TWI.h.
\r
49 * \section Sec_ExampleUsage Example Usage
\r
50 * The following snippet is an example of how this module may be used within a typical
\r
53 * <b>Low Level API Example:</b>
\r
55 * // Initialize the TWI driver before first use at 200KHz
\r
56 * TWI_Init(TWI_BIT_PRESCALE_1, TWI_BITLENGTH_FROM_FREQ(1, 200000));
\r
58 * // Start a write session to device at device address 0xA0, internal address 0xDC with a 10ms timeout
\r
59 * if (TWI_StartTransmission(0xA0 | TWI_ADDRESS_WRITE, 10) == TWI_ERROR_NoError)
\r
61 * TWI_SendByte(0xDC);
\r
63 * TWI_SendByte(0x01);
\r
64 * TWI_SendByte(0x02);
\r
65 * TWI_SendByte(0x03);
\r
67 * // Must stop transmission afterwards to release the bus
\r
68 * TWI_StopTransmission();
\r
71 * // Start a read session to device at address 0xA0, internal address 0xDC with a 10ms timeout
\r
72 * if (TWI_StartTransmission(0xA0 | TWI_ADDRESS_WRITE, 10) == TWI_ERROR_NoError)
\r
74 * TWI_SendByte(0xDC);
\r
75 * TWI_StopTransmission();
\r
77 * if (TWI_StartTransmission(0xA0 | TWI_ADDRESS_READ, 10) == TWI_ERROR_NoError)
\r
79 * uint8_t Byte1, Byte2, Byte3;
\r
81 * // Read three bytes, acknowledge after the third byte is received
\r
82 * TWI_ReceiveByte(&Byte1, false);
\r
83 * TWI_ReceiveByte(&Byte2, false);
\r
84 * TWI_ReceiveByte(&Byte3, true);
\r
86 * // Must stop transmission afterwards to release the bus
\r
87 * TWI_StopTransmission();
\r
92 * <b>High Level API Example:</b>
\r
94 * // Initialize the TWI driver before first use at 200KHz
\r
95 * TWI_Init(TWI_BIT_PRESCALE_1, TWI_BITLENGTH_FROM_FREQ(1, 200000));
\r
97 * // Start a write session to device at device address 0xA0, internal address 0xDC with a 10ms timeout
\r
98 * uint8_t InternalWriteAddress = 0xDC;
\r
99 * uint8_t WritePacket[3] = {0x01, 0x02, 0x03};
\r
101 * TWI_WritePacket(0xA0, 10, &InternalWriteAddress, sizeof(InternalWriteAddress),
\r
102 * &WritePacket, sizeof(WritePacket);
\r
104 * // Start a read session to device at address 0xA0, internal address 0xDC with a 10ms timeout
\r
105 * uint8_t InternalReadAddress = 0xDC;
\r
106 * uint8_t ReadPacket[3];
\r
108 * TWI_ReadPacket(0xA0, 10, &InternalReadAddress, sizeof(InternalReadAddress),
\r
109 * &ReadPacket, sizeof(ReadPacket);
\r
115 #ifndef __TWI_AVR8_H__
\r
116 #define __TWI_AVR8_H__
\r
119 #include "../../../Common/Common.h"
\r
122 #include <util/twi.h>
\r
124 /* Enable C linkage for C++ Compilers: */
\r
125 #if defined(__cplusplus)
\r
129 /* Preprocessor Checks: */
\r
130 #if !defined(__INCLUDE_FROM_TWI_H) && !defined(__INCLUDE_FROM_TWI_C)
\r
131 #error Do not include this file directly. Include LUFA/Drivers/Peripheral/TWI.h instead.
\r
134 #if !(defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB646__) || \
\r
135 defined(__AVR_AT90USB1287__) || defined(__AVR_AT90USB647__) || \
\r
136 defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__) || \
\r
137 defined(__AVR_ATmega32U6__))
\r
138 #error The TWI peripheral driver is not currently available for your selected microcontroller model.
\r
141 /* Public Interface - May be used in end-application: */
\r
143 /** TWI slave device address mask for a read session. Mask with a slave device base address to obtain
\r
144 * the correct TWI bus address for the slave device when reading data from it.
\r
146 #define TWI_ADDRESS_READ 0x01
\r
148 /** TWI slave device address mask for a write session. Mask with a slave device base address to obtain
\r
149 * the correct TWI bus address for the slave device when writing data to it.
\r
151 #define TWI_ADDRESS_WRITE 0x00
\r
153 /** Mask to retrieve the base address for a TWI device, which can then be ORed with \ref TWI_ADDRESS_READ
\r
154 * or \ref TWI_ADDRESS_WRITE to obtain the device's read and write address respectively.
\r
156 #define TWI_DEVICE_ADDRESS_MASK 0xFE
\r
158 /** Bit length prescaler for \ref TWI_Init(). This mask multiplies the TWI bit length prescaler by 1. */
\r
159 #define TWI_BIT_PRESCALE_1 ((0 << TWPS1) | (0 << TWPS0))
\r
161 /** Bit length prescaler for \ref TWI_Init(). This mask multiplies the TWI bit length prescaler by 4. */
\r
162 #define TWI_BIT_PRESCALE_4 ((0 << TWPS1) | (1 << TWPS0))
\r
164 /** Bit length prescaler for \ref TWI_Init(). This mask multiplies the TWI bit length prescaler by 16. */
\r
165 #define TWI_BIT_PRESCALE_16 ((1 << TWPS1) | (0 << TWPS0))
\r
167 /** Bit length prescaler for \ref TWI_Init(). This mask multiplies the TWI bit length prescaler by 64. */
\r
168 #define TWI_BIT_PRESCALE_64 ((1 << TWPS1) | (1 << TWPS0))
\r
170 /** Calculates the length of each bit on the TWI bus for a given target frequency. This may be used with
\r
171 * the \ref TWI_Init() function to convert a bus frequency to a number of clocks for the \c BitLength
\r
174 * \param[in] Prescale Prescaler set on the TWI bus.
\r
175 * \param[in] Frequency Desired TWI bus frequency in Hz.
\r
177 * \return Bit length in clocks for the given TWI bus frequency at the given prescaler value.
\r
179 #define TWI_BITLENGTH_FROM_FREQ(Prescale, Frequency) ((((F_CPU / (Prescale)) / (Frequency)) - 16) / 2)
\r
182 /** Enum for the possible return codes of the TWI transfer start routine and other dependant TWI functions. */
\r
183 enum TWI_ErrorCodes_t
\r
185 TWI_ERROR_NoError = 0, /**< Indicates that the command completed successfully. */
\r
186 TWI_ERROR_BusFault = 1, /**< A TWI bus fault occurred while attempting to capture the bus. */
\r
187 TWI_ERROR_BusCaptureTimeout = 2, /**< A timeout occurred whilst waiting for the bus to be ready. */
\r
188 TWI_ERROR_SlaveResponseTimeout = 3, /**< No ACK received at the nominated slave address within the timeout period. */
\r
189 TWI_ERROR_SlaveNotReady = 4, /**< Slave NAKed the TWI bus START condition. */
\r
190 TWI_ERROR_SlaveNAK = 5, /**< Slave NAKed whilst attempting to send data to the device. */
\r
193 /* Inline Functions: */
\r
194 /** Initializes the TWI hardware into master mode, ready for data transmission and reception. This must be
\r
195 * before any other TWI operations.
\r
197 * The generated SCL frequency will be according to the formula <pre>F_CPU / (16 + 2 * BitLength + 4 ^ Prescale)</pre>.
\r
199 * \attention The value of the \c BitLength parameter should not be set below 10 or invalid bus conditions may
\r
200 * occur, as indicated in the AVR8 microcontroller datasheet.
\r
202 * \param[in] Prescale Prescaler to use when determining the bus frequency, a \c TWI_BIT_PRESCALE_* value.
\r
203 * \param[in] BitLength Length of the bits sent on the bus.
\r
205 static inline void TWI_Init(const uint8_t Prescale, const uint8_t BitLength) ATTR_ALWAYS_INLINE;
\r
206 static inline void TWI_Init(const uint8_t Prescale, const uint8_t BitLength)
\r
208 TWCR |= (1 << TWEN);
\r
213 /** Turns off the TWI driver hardware. If this is called, any further TWI operations will require a call to
\r
214 * \ref TWI_Init() before the TWI can be used again.
\r
216 static inline void TWI_Disable(void) ATTR_ALWAYS_INLINE;
\r
217 static inline void TWI_Disable(void)
\r
219 TWCR &= ~(1 << TWEN);
\r
222 /** Sends a TWI STOP onto the TWI bus, terminating communication with the currently addressed device. */
\r
223 static inline void TWI_StopTransmission(void) ATTR_ALWAYS_INLINE;
\r
224 static inline void TWI_StopTransmission(void)
\r
226 TWCR = ((1 << TWINT) | (1 << TWSTO) | (1 << TWEN));
\r
229 /* Function Prototypes: */
\r
230 /** Begins a master mode TWI bus communication with the given slave device address.
\r
232 * \param[in] SlaveAddress Address of the slave TWI device to communicate with.
\r
233 * \param[in] TimeoutMS Timeout period within which the slave must respond, in milliseconds.
\r
235 * \return A value from the \ref TWI_ErrorCodes_t enum.
\r
237 uint8_t TWI_StartTransmission(const uint8_t SlaveAddress,
\r
238 const uint8_t TimeoutMS);
\r
240 /** Sends a byte to the currently addressed device on the TWI bus.
\r
242 * \param[in] Byte Byte to send to the currently addressed device
\r
244 * \return Boolean \c true if the recipient ACKed the byte, \c false otherwise
\r
246 bool TWI_SendByte(const uint8_t Byte);
\r
248 /** Receives a byte from the currently addressed device on the TWI bus.
\r
250 * \param[in] Byte Location where the read byte is to be stored.
\r
251 * \param[in] LastByte Indicates if the byte should be ACKed if false, NAKed if true.
\r
253 * \return Boolean \c true if the byte reception successfully completed, \c false otherwise.
\r
255 bool TWI_ReceiveByte(uint8_t* const Byte,
\r
256 const bool LastByte) ATTR_NON_NULL_PTR_ARG(1);
\r
258 /** High level function to perform a complete packet transfer over the TWI bus to the specified
\r
261 * \param[in] SlaveAddress Base address of the TWI slave device to communicate with.
\r
262 * \param[in] TimeoutMS Timeout for bus capture and slave START ACK, in milliseconds.
\r
263 * \param[in] InternalAddress Pointer to a location where the internal slave read start address is stored.
\r
264 * \param[in] InternalAddressLen Size of the internal device address, in bytes.
\r
265 * \param[in] Buffer Pointer to a buffer where the read packet data is to be stored.
\r
266 * \param[in] Length Size of the packet to read, in bytes.
\r
268 * \return A value from the \ref TWI_ErrorCodes_t enum.
\r
270 uint8_t TWI_ReadPacket(const uint8_t SlaveAddress,
\r
271 const uint8_t TimeoutMS,
\r
272 const uint8_t* InternalAddress,
\r
273 uint8_t InternalAddressLen,
\r
275 uint8_t Length) ATTR_NON_NULL_PTR_ARG(3);
\r
277 /** High level function to perform a complete packet transfer over the TWI bus from the specified
\r
280 * \param[in] SlaveAddress Base address of the TWI slave device to communicate with
\r
281 * \param[in] TimeoutMS Timeout for bus capture and slave START ACK, in milliseconds
\r
282 * \param[in] InternalAddress Pointer to a location where the internal slave write start address is stored
\r
283 * \param[in] InternalAddressLen Size of the internal device address, in bytes
\r
284 * \param[in] Buffer Pointer to a buffer where the packet data to send is stored
\r
285 * \param[in] Length Size of the packet to send, in bytes
\r
287 * \return A value from the \ref TWI_ErrorCodes_t enum.
\r
289 uint8_t TWI_WritePacket(const uint8_t SlaveAddress,
\r
290 const uint8_t TimeoutMS,
\r
291 const uint8_t* InternalAddress,
\r
292 uint8_t InternalAddressLen,
\r
293 const uint8_t* Buffer,
\r
294 uint8_t Length) ATTR_NON_NULL_PTR_ARG(3);
\r
296 /* Disable C linkage for C++ Compilers: */
\r
297 #if defined(__cplusplus)
\r