ATMEGA128RFA1-ZU Atmel, ATMEGA128RFA1-ZU Datasheet - Page 94

• Manufacturer Part Number: ATMEGA128RFA1-ZU
• Description: IC AVR MCU 2.4GHZ XCEIVER 64QFN
• Manufacturer: Atmel
• Series: ATMEGAr

Specifications of ATMEGA128RFA1-ZU

• Frequency: 2.4GHz
• Data Rate - Maximum: 2Mbps
• Modulation Or Protocol: 802.15.4 Zigbee
• Applications: General Purpose
• Power - Output: 3.5dBm
• Sensitivity: -100dBm
• Voltage - Supply: 1.8 V ~ 3.6 V
• Current - Receiving: 12.5mA
• Current - Transmitting: 14.5mA
• Data Interface: PCB, Surface Mount
• Memory Size: 128kB Flash, 4kB EEPROM, 16kB RAM
• Antenna Connector: PCB, Surface Mount
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-VFQFN, Exposed Pad
• Rf Ic Case Style: QFN
• No. Of Pins: 64
• Supply Voltage Range: 1.8V To 3.6V
• Operating Temperature Range: -40°C To +85°C
• Svhc: No SVHC (15-Dec-2010)
• Rohs Compliant: Yes
• Processor Series: ATMEGA128x
• Core: AVR8
• Data Bus Width: 8 bit
• Program Memory Type: Flash
• Program Memory Size: 128 KB
• Data Ram Size: 16 KB
• Interface Type: JTAG
• Maximum Clock Frequency: 16 MHz
• Number Of Programmable I/os: 38
• Number Of Timers: 6
• Operating Supply Voltage: 1.8 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVR128RFA1-EK1
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

9.8.8.4 Security Operation Modes
9.8.8.4.1 Electronic Code Book (ECB)
94
ATmega128RFA1
A 16-folded read access to registers AES_KEY returns the last round key of the
preceding security operation. This is the key required for the corresponding ECB
decryption operation after an ECB encryption operation. However the initial AES key
written to the security module in advance of an AES run (see step 1 in
page
AES run although it cannot be read from AES_KEY.
Before accessing the Key Buffer it must be ensured, that the internal address counter is
initialized correctly. This is the cases after Radio Transceiver Reset (see
Transceiver Pin Register on page
operation. After an interrupted buffer read or write access, Address pointer
reinitialization is recommended by a simple read access to the AES_CTRL register.
ECB is the basic operating mode of the security module and is configured by the
AES_CTRL register. The bit AES_MODE = 0 defines the ECB mode and bit AES_DIR
selects the direction to either encryption or decryption. The data to be processed has to
be written to registers AES_STATE.
A security operation can be started by writing the start command AES_REQUEST = 1
(AES_CTRL register).
The ECB encryption operation is illustrated in
shows the ECB decryption mode which is supported in a similar way.
Figure 9-35. ECB Mode - Encryption
Figure 9-36. ECB Mode - Decryption
Due to the nature of AES algorithm the initial key to be used when decrypting is not the
same as the one used for encryption. Instead it is the last round key. This last round
Note:
92) is not modified during an AES operation. This initial key is used for the next
Encryption
1. ECB decryption is not required for IEEE 802.15.4 or ZigBee security processing.
Key
The radio transceiver provides this functionality as an additional feature.
Decryption
Key
Block Cipher
Encryption
Ciphertext
Plaintext
Block Cipher
169) or a completed AES Encryption/ Decryption
Decryption
Ciphertext
Plaintext
Encryption
Key
Figure 9-35
Decryption
Key
below.
Block Cipher
Encryption
Ciphertext
Plaintext
8266A-MCU Wireless-12/09
Figure 9-36 below
Block Cipher
Decryption
Ciphertext
Plaintext
Table 9-25 on
TRXPR –