diff options
Diffstat (limited to 'LUFA/Drivers/Peripheral/AVR8/TWI_AVR8.h')
| -rw-r--r-- | LUFA/Drivers/Peripheral/AVR8/TWI_AVR8.h | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/LUFA/Drivers/Peripheral/AVR8/TWI_AVR8.h b/LUFA/Drivers/Peripheral/AVR8/TWI_AVR8.h index 705ef530c..0f31eca6f 100644 --- a/LUFA/Drivers/Peripheral/AVR8/TWI_AVR8.h +++ b/LUFA/Drivers/Peripheral/AVR8/TWI_AVR8.h @@ -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 |