AT86RF232 Atmel Corporation, AT86RF232 Datasheet - Page 85

• Manufacturer Part Number: AT86RF232
• Manufacturer: Atmel Corporation

Specifications of AT86RF232

• Max. Operating Frequency: 0 MHz
• Crypto Engine: AES
• Operating Voltage (vcc): 1.8 to 3.6
• Frequency Band: 2.4 GHz
• Max Data Rate (mb/s): 0.25
• Antenna Diversity: Yes
• External Pa Control: Yes
• Power Output (dbm): 3
• Receiver Sensitivity (dbm): -100
• Receive Current Consumption (ma): 11.8
• Transmit Current Consumption (ma): 13.8
• Link Budget (dbm): 103

8.2.3 Automatic FCS generation
8.2.4 Automatic FCS check
8321A–MCU Wireless–10/11
The leftmost bit (b
The leftmost bit (r
The automatic FCS generation is activated with register bit TX_AUTO_CRC_ON = 1
(reset value). This allows the Atmel AT86RF232 to compute the FCS autonomously.
For a frame with a frame length specified as N (3 ≤ N ≤ 127), the FCS is calculated on
the first N-2 octets in the Frame Buffer, and the resulting FCS field is transmitted in
place of the last two octets from the Frame Buffer.
If the radio transceiver’s automatic FCS generation is enabled, the Frame Buffer write
access can be stopped right after MAC payload. There is no need to write FCS dummy
bytes.
In RX_AACK mode, when a received frame needs to be acknowledged, the FCS of the
ACK frame is always automatically generated by the AT86RF232, independent of the
TX_AUTO_CRC_ON setting.
Example:
A frame transmission of length five with TX_AUTO_CRC_ON set, is started with a
Frame Buffer write access of five bytes (the last two bytes can be omitted). The first
three bytes are used for FCS generation; the last two bytes are replaced by the
internally calculated FCS.
An automatic FCS check is applied on each received frame with a frame length N ≥ 2.
Register bit RX_CRC_VALID (register 0x06, PHY_RSSI) is set if the FCS of a received
frame is valid. The register bit is updated when issuing interrupt IRQ_3 (TRX_END) and
remains valid until the next TRX_END interrupt caused by a new frame reception.
In RX_AACK mode, if FCS of the received frame is not valid, the radio transceiver
rejects the frame and the TRX_END interrupt is not issued.
In TX_ARET mode, the FCS and the sequence number of an ACK is automatically
checked. If one of these is not correct, the ACK is not accepted.
0010 0111 1001 1110.
0
0
) is transmitted first in time.
) is transmitted first in time. The FCS is in this case
AT86RF232
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