AT86RF230 Atmel Corporation, AT86RF230 Datasheet - Page 90

• Manufacturer Part Number: AT86RF230
• Manufacturer: Atmel Corporation

Specifications of AT86RF230

• Crypto Engine: No
• Operating Voltage (vcc): 1.8 to 3.6
• Frequency Band: 2.4 GHz
• Max Data Rate (mb/s): 0.25
• Antenna Diversity: No
• External Pa Control: No
• Power Output (dbm): 3
• Receiver Sensitivity (dbm): -101
• Receive Current Consumption (ma): 16.0
• Transmit Current Consumption (ma): 17.0
• Link Budget (dbm): 104

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AT86RF230
4. Sensitivity to continuous wave interferers
5. TRX_END_IRQ occurs sometimes too late in TX_ARET_ON state
6. TX_ARET ACK wait time too short
7. CCA Request is not executed
This behavior can be observed, if the procedure TX_ARET performs frame
retransmissions.
Fix/Workaround
Set register bit MAX_FRAME_RETRIES = 0 (register 0x2C) and implement frame
retries by software. A frame retransmission does not require downloading the frame
again, only TX_START command is necessary.
The maximum number of symbols waiting for an acknowledgment frame should be
54 symbols as defined in IEEE 802.15.4-2003. The implemented waiting time is
46 symbols.
Fix/Workaround
None
A requested CCA may be rejected without execution. In this case the CCA_DONE bit
indicates “CCA calculation in progress” even though the calculation must be finished
already.
Fix/Workaround
The TRX_STATUS is RX_ON. To initiate a CCA request, switch to PLL_ON state
and back to RX_ON state. Immediately after the state change initiate a CCA request.
It is not necessary to confirm the state changes.
Switching to RX_ON is not executed during BUSY_TX_ARET but immediately after
BUSY_TX_ARET has completed. This enables the receiver to receive a frame which
arrives shortly before the end of the ACK wait period. In this case TRAC_STATUS is
not accidentally set to SUCCESS and is still correct (NO_ACK), as long as the frame
is received. That means the software has additional time to read the
TRAC_STATUS.
Using the workaround mentioned above, the failure occurrence is considerably
reduced. A wrong TRAC_STATUS can still be observed, but very seldom (one of
million transmissions).
Due to the high receiver sensitivity continuous wave interferers may cause
RX_START interrupts. This may result in missed frames since the receiver is kept
busy detecting preambles and SFD. One cause of continuous wave interferers may
be due to crosstalk from clock.
Fix/Workaround
For further details see application note AVR2005 "Design Considerations for the
AT86RF230".
o
o
o
o
o
set TRX_CMD = RX_ON
wait for TRX_END IRQ
read TRAC_STATUS
set TRX_CMD = TX_ARET_ON
poll for TRX_STATUS == TX_ARET_ON
5131E-MCU Wireless-02/09