Added new high level TWI packet read/write commands, altered behaviour of the TWI_StartTransmission() function.

Spell check source code files.
This commit is contained in:
Dean Camera 2011-01-13 22:56:49 +00:00
parent 9c7594e7db
commit 70d55f6e0c
13 changed files with 225 additions and 92 deletions

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@ -87,13 +87,13 @@
* for (uint16_t i = 0; i < DATAFLASH_PAGE_SIZE; i++)
* Dataflash_SendByte(WriteBuffer[i]);
*
* // Commit the Dataflash's first memory buffer to the non-voltatile FLASH memory
* // Commit the Dataflash's first memory buffer to the non-volatile FLASH memory
* printf("Committing page to non-volatile memory page index 5:\r\n");
* Dataflash_SendByte(DF_CMD_BUFF1TOMAINMEMWITHERASE);
* Dataflash_SendAddressBytes(5, 0);
* Dataflash_WaitWhileBusy();
*
* // Read the page from non-voltatile FLASH memory into the Dataflash's second memory buffer
* // Read the page from non-volatile FLASH memory into the Dataflash's second memory buffer
* printf("Reading data into second dataflash buffer:\r\n");
* Dataflash_SendByte(DF_CMD_MAINMEMTOBUFF2);
* Dataflash_SendAddressBytes(5, 0);

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@ -56,7 +56,7 @@
* ADC_Init(ADC_FREE_RUNNING | ADC_PRESCALE_128);
* Temperature_Init();
*
* // Display converted temperature in degrees Celcius
* // Display converted temperature in degrees Celsius
* printf("Current Temperature: %d Degrees\r\n", Temperature_GetTemperature());
* \endcode
*

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@ -35,9 +35,9 @@
* different sizes to suit different needs.
*
* Note that for each buffer, insertion and removal operations may occur at the same time (via
* a multithreaded ISR based system) however the same kind of operation (two or more insertions
* a multi-threaded ISR based system) however the same kind of operation (two or more insertions
* or deletions) must not overlap. If there is possibility of two or more of the same kind of
* operating occuring at the same point in time, atomic (mutex) locking should be used.
* operating occurring at the same point in time, atomic (mutex) locking should be used.
*/
/** \ingroup Group_MiscDrivers
@ -52,9 +52,9 @@
* different sizes to suit different needs.
*
* Note that for each buffer, insertion and removal operations may occur at the same time (via
* a multithreaded ISR based system) however the same kind of operation (two or more insertions
* a multi-threaded ISR based system) however the same kind of operation (two or more insertions
* or deletions) must not overlap. If there is possibility of two or more of the same kind of
* operating occuring at the same point in time, atomic (mutex) locking should be used.
* operating occurring at the same point in time, atomic (mutex) locking should be used.
*
* \section Sec_ExampleUsage Example Usage
* The following snippet is an example of how this module may be used within a typical

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@ -49,13 +49,16 @@
* The following snippet is an example of how this module may be used within a typical
* application.
*
* <b>Low Level API Example:</b>
* \code
* // Initialise the TWI driver before first use
* TWI_Init();
*
* // Start a write session to device at address 0xA0 with a 10ms timeout
* // Start a write session to device at device address 0xA0, internal address 0xDC with a 10ms timeout
* if (TWI_StartTransmission(0xA0 | TWI_ADDRESS_WRITE, 10))
* {
* TWI_SendByte(0xDC);
*
* TWI_SendByte(0x01);
* TWI_SendByte(0x02);
* TWI_SendByte(0x03);
@ -64,21 +67,47 @@
* TWI_StopTransmission();
* }
*
* // Start a read session to device at address 0xA0 with a 10ms timeout
* if (TWI_StartTransmission(0xA0 | TWI_ADDRESS_READ, 10))
* // Start a read session to device at address 0xA0, internal address 0xDC with a 10ms timeout
* if (TWI_StartTransmission(0xA0 | TWI_ADDRESS_WRITE, 10))
* {
* uint8_t Byte1, Byte2, Byte3;
*
* // 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_SendByte(0xDC);
* TWI_StopTransmission();
*
* if (TWI_StartTransmission(0xA0 | TWI_ADDRESS_READ, 10))
* {
* uint8_t Byte1, Byte2, Byte3;
*
* // 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();
* }
* }
* \endcode
*
* <b>High Level API Example:</b>
* \code
* // Initialise the TWI driver before first use
* TWI_Init();
*
* // 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
*
* @{
*/
@ -90,6 +119,7 @@
#include <avr/io.h>
#include <stdbool.h>
#include <stdio.h>
#include <util/twi.h>
#include <util/delay.h>
@ -108,12 +138,29 @@
/** 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.
*/
#define TWI_ADDRESS_READ 0x00
#define TWI_ADDRESS_READ 0x00
/** 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.
*/
#define TWI_ADDRESS_WRITE 0x01
#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
/* Enums: */
/** Enum for the possible return codes of the TWI transfer start routine and other dependant TWI functions. */
enum TWI_ErrorCodes_t
{
TWI_ERROR_NoError = 0, /**< Indicates that the command completed sucessfully. */
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. */
};
/* Inline Functions: */
/** Initialises the TWI hardware into master mode, ready for data transmission and reception. This must be
@ -163,8 +210,8 @@
*
* \return Boolean \c true if the byte reception successfully completed, \c false otherwise
*/
static inline bool TWI_ReceiveByte(uint8_t* const Byte,
const bool LastByte)
static inline uint8_t TWI_ReceiveByte(uint8_t* const Byte,
const bool LastByte)
{
uint8_t TWCRMask = ((1 << TWINT) | (1 << TWEN));
@ -184,10 +231,44 @@
* \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
*
* \return Boolean \c true if the device is ready for data, \c false otherwise
* \return A value from the \ref TWI_ErrorCodes_t enum
*/
bool TWI_StartTransmission(const uint8_t SlaveAddress,
const uint8_t TimeoutMS);
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
*/
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);
/* Disable C linkage for C++ Compilers: */
#if defined(__cplusplus)

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@ -7,8 +7,8 @@
#include "TWI.h"
bool TWI_StartTransmission(const uint8_t SlaveAddress,
const uint8_t TimeoutMS)
uint8_t TWI_StartTransmission(const uint8_t SlaveAddress,
const uint8_t TimeoutMS)
{
for (;;)
{
@ -33,17 +33,17 @@ bool TWI_StartTransmission(const uint8_t SlaveAddress,
continue;
default:
TWCR = (1 << TWEN);
return false;
return TWI_ERROR_BusFault;
}
}
_delay_us(10);
}
if (!(BusCaptured))
if (!(TimeoutRemaining))
{
TWCR = (1 << TWEN);
return false;
return TWI_ERROR_BusCaptureTimeout;
}
TWDR = SlaveAddress;
@ -59,17 +59,85 @@ bool TWI_StartTransmission(const uint8_t SlaveAddress,
}
if (!(TimeoutRemaining))
return false;
return TWI_ERROR_SlaveResponseTimeout;
switch (TWSR & TW_STATUS_MASK)
{
case TW_MT_SLA_ACK:
case TW_MR_SLA_ACK:
return true;
return TWI_ERROR_NoError;
default:
TWCR = ((1 << TWINT) | (1 << TWSTO) | (1 << TWEN));
return false;
return TWI_ERROR_SlaveNotReady;
}
}
}
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)
{
uint8_t ErrorCode;
if ((ErrorCode = TWI_WritePacket(SlaveAddress, TimeoutMS, InternalAddress, InternalAddressLen,
NULL, 0)) != TWI_ERROR_NoError)
{
return ErrorCode;
}
if ((ErrorCode = TWI_StartTransmission((SlaveAddress & TWI_DEVICE_ADDRESS_MASK) | TWI_ADDRESS_READ,
TimeoutMS)) == TWI_ERROR_NoError)
{
while (Length--)
{
if (!(TWI_ReceiveByte(Buffer++, (Length == 0))))
{
ErrorCode = TWI_ERROR_SlaveNAK;
break;
}
}
TWI_StopTransmission();
}
return ErrorCode;
}
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)
{
uint8_t ErrorCode;
if ((ErrorCode = TWI_StartTransmission((SlaveAddress & TWI_DEVICE_ADDRESS_MASK) | TWI_ADDRESS_WRITE,
TimeoutMS)) == TWI_ERROR_NoError)
{
while (InternalAddressLen--)
{
if (!(TWI_SendByte(*(InternalAddress++))))
{
ErrorCode = TWI_ERROR_SlaveNAK;
break;
}
}
while (Length--)
{
if (!(TWI_SendByte(*(Buffer++))))
{
ErrorCode = TWI_ERROR_SlaveNAK;
break;
}
}
TWI_StopTransmission();
}
return ErrorCode;
}

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@ -189,7 +189,7 @@
enum CDC_DescriptorSubtypes_t
{
CDC_DSUBTYPE_CSInterface_Header = 0x00, /**< CDC class-specific Header functional descriptor. */
CDC_DSUBTYPE_CSInterface_CallManagement = 0x01, /**< CDC class-specific Call Managment functional descriptor. */
CDC_DSUBTYPE_CSInterface_CallManagement = 0x01, /**< CDC class-specific Call Management functional descriptor. */
CDC_DSUBTYPE_CSInterface_ACM = 0x02, /**< CDC class-specific Abstract Control Model functional descriptor. */
CDC_DSUBTYPE_CSInterface_DirectLine = 0x03, /**< CDC class-specific Direct Line functional descriptor. */
CDC_DSUBTYPE_CSInterface_TelephoneRinger = 0x04, /**< CDC class-specific Telephone Ringer functional descriptor. */
@ -280,7 +280,7 @@
* must be \ref CDC_DSUBTYPE_CSInterface_ACM.
*/
uint8_t Capabilities; /**< Capabilities of the ACM interface, given as a bit mask. For most devices,
* this should be set to a fixed value of 0x06 - for other capabiltiies, refer
* this should be set to a fixed value of 0x06 - for other capabilities, refer
* to the CDC ACM specification.
*/
} USB_CDC_Descriptor_FunctionalACM_t;
@ -303,7 +303,7 @@
* must be \ref CDC_DSUBTYPE_CSInterface_ACM.
*/
uint8_t bmCapabilities; /**< Capabilities of the ACM interface, given as a bit mask. For most devices,
* this should be set to a fixed value of 0x06 - for other capabiltiies, refer
* this should be set to a fixed value of 0x06 - for other capabilities, refer
* to the CDC ACM specification.
*/
} USB_CDC_StdDescriptor_FunctionalACM_t;

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@ -95,8 +95,8 @@
* after connection before the enumeration process can start or incorrect operation will
* occur.
*
* The default delay value may be overridden in the user project makefile by definining the
* \c HOST_DEVICE_SETTLE_DELAY_MS token to tbe required delay in milliseconds, and passed to the
* The default delay value may be overridden in the user project makefile by defining the
* \c HOST_DEVICE_SETTLE_DELAY_MS token to the required delay in milliseconds, and passed to the
* compiler using the -D switch.
*/
#define HOST_DEVICE_SETTLE_DELAY_MS 1000

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@ -308,7 +308,7 @@
* changed in value.
* \n\n
*
* \note When the controller is initialized into UID autodetection mode, this variable will hold the
* \note When the controller is initialized into UID auto-detection mode, this variable will hold the
* currently selected USB mode (i.e. \ref USB_MODE_Device or \ref USB_MODE_Host). If the controller
* is fixed into a specific mode (either through the \c USB_DEVICE_ONLY or \c USB_HOST_ONLY compile time
* options, or a limitation of the USB controller in the chosen device model) this will evaluate to