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Add new TWI_BITLENGTH_FROM_FREQ() macro to the AVR8 TWI peripheral driver.

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Change Delay_MS() to accept a 16-bit parameter rather than an 8-bit parameter for longer possible delays.

Minor documentation improvements.
This commit is contained in:
Dean Camera 2011-09-02 04:38:56 +00:00
parent 88d022a752
commit 413438eb23
3 changed files with 25 additions and 6 deletions
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16
LUFA/Drivers/Peripheral/AVR8/Serial_AVR8.h
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@ -97,15 +97,23 @@
/* Public Interface - May be used in end-application: */
/* Macros: */
/** Macro for calculating the baud value from a given baud rate when the U2X (double speed) bit is
/** Macro for calculating the baud value from a given baud rate when the \c U2X (double speed) bit is
* not set.
*
* \param[in] Baud Target serial UART baud rate.
*
* \return Closest UBRR register value for the given UART frequency.
*/
#define SERIAL_UBBRVAL(baud) ((((F_CPU / 16) + (baud / 2)) / (baud)) - 1)
#define SERIAL_UBBRVAL(Baud) ((((F_CPU / 16) + (Baud / 2)) / (Baud)) - 1)
/** Macro for calculating the baud value from a given baud rate when the U2X (double speed) bit is
/** Macro for calculating the baud value from a given baud rate when the \c U2X (double speed) bit is
* set.
*
* \param[in] Baud Target serial UART baud rate.
*
* \return Closest UBRR register value for the given UART frequency.
*/
#define SERIAL_2X_UBBRVAL(baud) ((((F_CPU / 8) + (baud / 2)) / (baud)) - 1)
#define SERIAL_2X_UBBRVAL(Baud) ((((F_CPU / 8) + (Baud / 2)) / (Baud)) - 1)
/* Function Prototypes: */
/** Transmits a given string located in program space (FLASH) through the USART.

11
LUFA/Drivers/Peripheral/AVR8/TWI_AVR8.h
View file

@ -167,6 +167,17 @@
/** 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))
/** Calculates the length of each bit on the TWI bus for a given target frequency. This may be used with
* the \ref TWI_Init() function to convert a bus frequency to a number of clocks for the \c BitLength
* parameter.
*
* \param[in] Prescaler Prescaler set on the TWI bus.
* \param[in] Frequency Desired TWI bus frequency in Hz.
*
* \return Bit length in clocks for the given TWI bus frequency at the given prescaler value.
*/
#define TWI_BITLENGTH_FROM_FREQ(Prescale, Frequency) ((((F_CPU / (Prescale)) / (Frequency)) - 16) / 2)
/* Enums: */
/** Enum for the possible return codes of the TWI transfer start routine and other dependant TWI functions. */
enum TWI_ErrorCodes_t