7

8393CS-MCU Wireless-09/14

ATmega256/128/64RFR2

3.2.22 CLKI

Input to the clock system. If selected, it provides the operating clock of the

microcontroller.

3.3 Unused Pins

Floating pins can cause power dissipation in the digital input stage. They should be

connected to an appropriate source. In normal operation modes the internal pull-up

resistors can be enabled (in Reset all GPIO are configured as input and the pull-up

resistors are still not enabled).

Bi-directional I/O pins shall not be connected to ground or power supply directly.

The digital input pins TST and CLKI must be connected. If unused pin TST can be

connected to AVSS while CLKI should be connected to DVSS.

Output pins are driven by the device and do not float. Power supply pins respective

ground supply pins are connected together internally.

XTAL1 and XTAL2 shall never be forced to supply voltage at the same time.

3.4 Configuration summary

According to the application requirements a variable memory size allows to optimize

current consumption and leakage current.

Table 3-1 Memory Configuration

Device

Flash

EEPROM

SRAM

ATmega256RFR2

256KB

8KB

32KB

ATmega128RFR2

128KB

4KB

16KB

ATmega64RFR2

64KB

2KB

8KB

Package and associated pin configuration are the same for all devices providing full

functionality to the application.

Table 3-2 System Configuration

Device

Package

GPIO

Serial IF

ADC channel

ATmega256RFR2

QFN

38

2 USART, SPI, TWI

8

ATmega128RFR2

QFN

38

2 USART, SPI, TWI

8

ATmega64RFR2

QFN

38

2 USART, SPI, TWI

8

The devices are optimized for applications based on the ZigBee and the IEEE 802.15.4

specification. Having application stack, network layer, sensor interface and an excellent

power control combined in a single chip many years of operation should be possible.

Table 3-3 Application Profile

Device

Application

ATmega256RFR2

Large Network Coordinator / Router for IEEE 802.15.4 / ZigBee Pro

ATmega128RFR2

Network Coordinator / Router for IEEE 802.15.4

ATmega64RFR2

End node device / network processor