ATMEGA128RZAV-8MU Atmel, ATMEGA128RZAV-8MU Datasheet - Page 55

• Manufacturer Part Number: ATMEGA128RZAV-8MU
• Description: MCU ATMEGA1281/AT86RF230 64-QFN
• Manufacturer: Atmel
• Series: ATMEGAr

Specifications of ATMEGA128RZAV-8MU

• Frequency: 2.4GHz
• Data Rate - Maximum: 2Mbps
• Modulation Or Protocol: 802.15.4 Zigbee
• Applications: General Purpose
• Power - Output: 3dBm
• Sensitivity: -101dBm
• Voltage - Supply: 1.8 V ~ 3.6 V
• Data Interface: PCB, Surface Mount
• Memory Size: 128kB Flash, 4kB EEPROM, 8kB RAM
• Antenna Connector: PCB, Surface Mount
• Package / Case: 64-QFN
• For Use With: ATAVRISP2 - PROGRAMMER AVR IN SYSTEMATJTAGICE2 - AVR ON-CHIP D-BUG SYSTEMATSTK501 - ADAPTER KIT FOR 64PIN AVR MCUATSTK500 - PROGRAMMER AVR STARTER KIT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Operating Temperature: -
• Current - Transmitting: -
• Current - Receiving: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

8.6.2 CCA Configuration and Request
8.6.3 Data Interpretation
8.6.4 Register Description
5131E-MCU Wireless-02/09
Bit
0x01
Read/Write
Reset value
Bit
0x01
Read/Write
Reset value
The CCA modes are configurable via register 0x08 (PHY_CC_CCA).
The 4 bit value CCA_ED_THRES of register 0x09 (CCA_THRES) defines the received
power threshold of the “energy above threshold” algorithm. The threshold is calculated
by RSSI_BASE_VAL+2•CCA_ED_THRES [dBm].
Using the Basic Operating Mode, a CCA request can be initiated manually by setting
CCA_REQUEST = 1 in register 0x08 (PHY_CC_CCA), if the AT86RF230 is in any RX
state. The CCA computation is done over eight symbol periodes and the result is
accessible 140 µs after the request.
Note, it is not recommended to initiate manually a CCA measurement when using the
Extended Operating Mode.
The current channel status (CCA_STATUS) and the CCA completion status
(CCA_DONE) are accessible in register 0x01 (TRX_STATUS). Note, a read access to
this register clears register bits CCA_DONE and CCA_STATUS.
The completion of a measurement cycle is indicated by CCA_DONE = 1. If the radio
transceiver detected no signal (idle channel) during the measurement cycle, the
CCA_STATUS bit is set to 1.
When using the “energy above threshold” algorithm (mode 1 and mode 3) any received
power above CCA_ED_THRES level is interpreted as a busy channel. The “carrier
sense” algorithm (mode 2 and mode 3) reports a busy channel when detecting a
IEEE 802.15.4 signal above the RSSI_BASE_VAL (see parameter 11.7.16). The radio
transceiver is also able to detect signals below this value, but the detection probability
decreases with the signal power. It is almost zero at the radio transceivers sensitivity
level (see parameter 11.7.1).
Register 0x01 (TRX_STATUS)
The TRX_STATUS register signals the current state of the radio transceiver as well as
the status of the CCA measurement. Note, a read access to the register clears bits
CCA_DONE and CCA_STATUS.
• Bit 7 – CCA_DONE
This register indicates if a CCA request is completed. Each read access to register
0x01 resets the CCA_DONE bit.
CCA_DONE
R
R
7
0
3
0
CCA_STATUS
R
R
6
0
2
0
TRX_STATUS
Reserved
R
R
5
0
1
0
TRX_STATUS
AT86RF230
R
R
4
0
0
0
TRX_STATUS
TRX_STATUS
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