Texas Instruments Chipcon CC2400DBK, Руководство пользователя, Страница: 23 / 31

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Figure 13: AVR Studio AVRISP Fuses Window
RC oscillator
The internal RC oscillator is used as reference time base. The oscillator frequency is
relatively independent of temperature and operating voltage. Its nominal frequency is 8 MHz.
A calibration feature utilising a calibration word programmed into the microcontroller at the
factory ensures that the oscillator frequency is equal from unit to unit. The calibration value is
stored at a fixed location in the EEPROM of the processor.
Microcontroller EEPROM mapping
The following map shows the data location. To customize the CC2400DB for a different
frequency, the EEPROM data can be replaced by new values found using the calibration
software. Please contact Chipcon Technical Support.
Note:
If a different RC oscillator frequency is used, a new calibration must be performed for the
desired frequency and stored at the correct location in EEPROM. The bootloader uses the
RS-232, so by changing the frequency the bootloader must be reprogrammed with the correct
baud setting for the frequency of choice. Please contact Chipcon Technical Support
EEPROM
Address (hex)
Data Reference Comment
0x01FF Calibration Value Calibration value is
only for 8 MHz