User's Manual

AVR2044

8339A-AVR-09/10

organization and SPI interface is used because of its small package, low voltage and

low power operation.

Compared to Atmega1281V based RCB’s, the ID-EEPROM interface has been

designed in a different way. Accessing the ID-EEPROM requires PG5 set to logic low.

This pin is not used on Atmega1281V based RCB’s, refer to Figure 5-3 for details.

Figure 5-3. ID-EEPROM Access Decoding Logic

The ID-EEPROM data is written during board production test with

• A unique serial number,

• MAC address

• Calibration values.

Calibration values are to be used to optimize radio transceiver performance.

Final products do not require this external ID-EEPROM functionality. All data can

directly be stored in the Atmega128RFA1 internal EEPROM. The ID-EEPROM is

placed for convenience, to simplify microcontroller firmware development.

Table 5-1 shows the data structure of the ID-EEPROM. The Cal RC values can be

used as a start value for the RC calibration algorithm. The Cal OSC 16 MHz value

can simply be copied to the corresponding radio transceiver register to reduce the

frequency deviation. However, the 16 MHz crystal is guarantied to deviate less than

20 ppm at room temperature, from the actual 16 MHz value without any calibration

adjustment. When the Cal OSC 16 MHz value is applied, the deviation is less than

5 ppm at room temperature.

Table 5-1 ID-EEPROM Mapping

Address Name Type Description

0x00 MAC address uint64 MAC address

for the 802.15.4 node,

little endian byte order