ATmega1284PR231 Atmel Corporation, ATmega1284PR231 Datasheet - Page 136

• Manufacturer Part Number: ATmega1284PR231
• Manufacturer: Atmel Corporation

Specifications of ATmega1284PR231

• Flash (kbytes): 128 Kbytes
• Max. Operating Frequency: 20 MHz
• Max I/o Pins: 32
• Spi: 3
• Twi (i2c): 1
• Uart: 2
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Crypto Engine: AES
• Sram (kbytes): 16
• Eeprom (bytes): 4096
• Operating Voltage (vcc): 1.8 to 3.6
• Timers: 3
• Frequency Band: 2.4 GHz
• Max Data Rate (mb/s): 2
• Antenna Diversity: Yes
• External Pa Control: Yes
• Power Output (dbm): 3
• Receiver Sensitivity (dbm): -101
• Receive Current Consumption (ma): 13.2
• Transmit Current Consumption (ma): 14.4
• Link Budget (dbm): 104

11.2
11.2.1
11.2.2
8111C–MCU Wireless–09/09
Random Number Generator
Overview
Register Description
The AT86RF231 incorporates a 2-bit truly random number generator by observation of noise.
This random number can be used to:
The random number is updated every t
values are stored in register bits RND_VALUE (register 0x06, PHY_RSSI).
Register 0x06 (PHY_RSSI):
Register 0x06 (PHY_RSSI) is a multi purpose register to indicate FCS validity, to provide ran-
dom numbers and an RSSI value.
• Bit 7 - RX_CRC_VALID
Refer to register description in
• Bit [6:5] - RND_VALUE
The 2-bit random value can be retrieved by reading register bits RND_VALUE. Note that the
radio transceiver shall be in Basic Operating Mode receive state. The values are updated each
t
• Bit [4:0] - RSSI
Refer to register description in
Note:
TR29
Bit
+0x06
Read/Write
Reset Value
• Generate random seeds for CSMA-CA algorithm
• Generate random values for AES key generation
= 1 µs.
Ensure that register bit RX_PDT_DIS (register 0x15, RX_SYN) is set to 0 at least 1 µs before
reading a random value.
RX_CRC_VALID
7
R
0
6
R
0
Section 8.2.5 “Register Description” on page
Section 8.3.4 “Register Description” on page
RND_VALUE
5
R
0
TR29
= 1 µs in Basic Operation Mode receive states. The
4
R
0
3
R
0
RSSI
2
R
0
see
see
Section 7.2
Section 11.1
1
R
0
AT86RF231
87.
90.
0
R
0
PHY_RSSI
136