ATMEGA128RFA1-ZU Atmel, ATMEGA128RFA1-ZU Datasheet - Page 68

• 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

9.5.3.2 Reading RSSI
9.5.3.3 Data Interpretation
9.5.4 Energy Detection (ED)
9.5.4.1 Overview
68
ATmega128RFA1
received signal strength is evaluated. The RSSI provides the basis for an ED
measurement. See section
In Basic Operating Mode the RSSI value is valid in any receive state, and is updated
every t
It is not recommended to read the RSSI value when using the Extended Operating
Mode. The automatically generated ED value should then be used (see section
Detection (ED)"
The RSSI value is a 5-bit value indicating the receive power in steps of 3 dB and with a
range of 0- 28.
An RSSI value of 0 indicates a receiver RF input power of P
value in the range of 1 to 28, the RF input power can be calculated as follows:
Figure 9-17. Mapping between RSSI Value and Received Input Power
The Energy Detection (ED) module is characterized by:
• 85 unique energy levels defined;
• 1 dB resolution.
The receiver ED measurement is used by the network layer as part of a channel
selection algorithm. It is an estimation of the received signal power within the bandwidth
of an IEEE 802.15.4 channel. No attempt is made to identify or decode signals on the
channel. The ED value is calculated by averaging RSSI values over eight symbols
(128 µs).
-100
-10
-20
-30
-40
-50
-60
-70
-80
-90
10
0
TR25
P
0
RF
= 2 s to register PHY_RSSI.
= RSSI_BASE_VAL + 3 • (RSSI - 1) [dBm]
2
below).
Measured
Ideal
4
6
"Energy Detection (ED)" below
8
10
12
14
RSSI
16
18
for details.
20
RF
< -90 dBm. For an RSSI
22
8266A-MCU Wireless-12/09
24
26
28
"Energy
30