Unused Pins; Configuration Summary - Atmel ATmega256RFR2 Manual

3.2.22 CLKI

3.3 Unused Pins

3.4 Configuration summary

8393CS-MCU Wireless-09/14
Input to the clock system. If selected, it provides the operating clock of the
microcontroller.
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.
According to the application requirements a variable memory size allows to optimize
current consumption and leakage current.
Table 3-1 Memory Configuration
Device
ATmega256RFR2
ATmega128RFR2
ATmega64RFR2
Package and associated pin configuration are the same for all devices providing full
functionality to the application.
Table 3-2 System Configuration
Device
ATmega256RFR2
ATmega128RFR2
ATmega64RFR2
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
ATmega256RFR2
ATmega128RFR2
ATmega64RFR2
ATmega256/128/64RFR2
Flash
256KB
128KB
64KB
Package GPIO
QFN 38
QFN 38
QFN 38
Application
Large Network Coordinator / Router for IEEE 802.15.4 / ZigBee Pro
Network Coordinator / Router for IEEE 802.15.4
End node device / network processor
EEPROM
8KB
4KB
2KB
Serial IF
2 USART, SPI, TWI
2 USART, SPI, TWI
2 USART, SPI, TWI
SRAM
32KB
16KB
8KB
ADC channel
8
8
8
7