ATMEGA128RFA1-ZU Atmel, ATMEGA128RFA1-ZU Datasheet - Page 59

• 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

8266B-MCU Wireless-03/11
Overview
The implemented TX_ARET algorithm is shown in
In TX_ARET mode, the radio transceiver first executes the CSMA-CA algorithm, as
defined by IEEE 802.15.4–2006, section 7.5.1.4, initiated by a transmit start event. If
the channel is IDLE a frame is transmitted from the Frame Buffer. If the
acknowledgement frame is requested the radio transceiver additionally checks for an
ACK reply.
A TRX24_TX_END interrupt indicates the completion of the TX_ARET transmit
transaction.
Description
Configuration and address bits are to be set in TRX_OFF or PLL_ON state prior to
switching to TX_ARET mode. It is further recommended to transfer the PSDU data to
the Frame Buffer in advance. The transaction is started by either writing SLPTR=1 as
described in section
TX_START command to register TRX_STATE.
If the CSMA-CA detects a busy channel, it is retried as specified by bits
MAX_CSMA_RETRIES of register XAH_CTRL_0. In case that CSMA-CA does not
detect a clear channel after MAX_CSMA_RETRIES it aborts the TX_ARET transaction,
issues a TRX24_TX_END interrupt and sets the value of the TRAC_STATUS register
bits to CHANNEL_ACCESS_FAILURE.
During transmission of a frame the radio transceiver parses bit 5 (ACK Request) of the
MAC header (MHR) frame control field of the PSDU data (PSDU octet #1) to be
transmitted to check if an ACK reply is expected.
If an ACK is expected the radio transceiver automatically switches into receive mode to
wait for a valid ACK reply. After receiving an ACK frame the Frame Pending subfield of
that frame is parsed and the status register bits TRAC_STATUS are updated
accordingly (see
Frame Buffer content. Transmit data in the Frame Buffer is not changed during the
entire TX_ARET transaction. Received frames other than the expected ACK frame are
discarded.
If no valid ACK is received or after timeout of 54 symbol periods (864 µs), the radio
transceiver retries the entire transaction (including CSMA-CA) until the maximum
number of retransmissions as set by the bits MAX_FRAME_RETRIES in register
XAH_CTRL_0 is exceeded.
After that, the microcontroller may read the value of the bits TRAC_STATUS of register
TRX_STATE to verify whether the transaction was successful or not. The register bits
are set according to the following cases:
Table 9-16. Interpretation of the TRAC_STATUS register bits
Value
0
1
3
Name
SUCCESS
SUCCESS_DATA_PENDING
CHANNEL_ACCESS_FAILURE
Table 9-16
"Transceiver Pin Register TRXPR" on page 33
below). This receive procedure does not overwrite the
Description
The transaction was responded by a valid
ACK, or, if no ACK is requested, after a
successful frame transmission
Equivalent to SUCCESS; indicates pending
frame data according to the MHR frame
control field of the received ACK response
Channel is still busy after
MAX_CSMA_RETRIES of CSMA-CA
Figure 9-12 on
ATmega128RFA1
page 58.
or writing a
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