AT86RF230_09 ATMEL [ATMEL Corporation], AT86RF230_09 Datasheet - Page 60

• Manufacturer Part Number: AT86RF230_09
• Description: Low Power 2.4 GHz Transceiver for ZigBee, IEEE 802.15.4, 6LoWPAN, RF4CE and ISM
• Manufacturer: ATMEL [ATMEL Corporation]

9.3 Frame Buffer
9.3.1 Frame Buffer Data Management
9.3.2 User accessible Frame Content
60
AT86RF230
The AT86RF230 contains a 128 byte dual port SRAM. One port is connected to the SPI
interface, the other to the internal TX/RX BBP port. For data communication both ports
are independent and simultaneously accessible. Access conflicts are indicated by a
TRX under run (TRX_UR) interrupt.
The Frame Buffer is used for the TX and RX operation of the device and can keep one
IEEE 802.15.4-2003 TX or one RX frame of maximum length at a time.
Note, a Frame Buffer access is only possible if the digital voltage regulator is turned on.
This is the case in all device states except in SLEEP and P_ON.
Data stored in Frame Buffer (received data or data to be transmitted) remains valid as
long as
• No new frame is written into the buffer via SPI
• No new frame is received (in any BUSY_RX state)
• No state change into SLEEP state is made
If the radio transceiver is in any RX state an incoming frame with valid SFD field
overwrites the Frame Buffer content 32 µs after the RX_START interrupt occurs, even if
the RX_START interrupt is disabled. Thus the Frame Buffer content should be
uploaded to the microcontroller before the next SFD is received. To avoid an
unintended Frame Buffer overwrite a state change to PLL_ON immediately after the
frame reception (TRX_END interrupt) is recommended.
Using the Extended Operating Mode states TX_ARET_ON or TX_ARET_ON_NOCLK,
the radio transceiver switches to RX (after successful frame transmission), if an
acknowledgement was requested in FCF. Received frames are evaluated but not
stored in the Frame Buffer in these states. This allows the radio transceiver to wait for
an acknowledgement frame and retry the data frame transmission without downloading
them again.
A radio transceiver state change, except a transition to SLEEP, does not affect the
Frame Buffer contents. If the radio transceiver is forced into SLEEP, the Frame Buffer is
powered off and the stored data gets lost.
The AT86RF230 supports an IEEE 802.15.4-2003 compliant frame format as shown in
Figure 9-1.
Register Bits
Value [3:0]
0xC
0xD
0xB
0xE
0xF
Output Power [dBm]
-12.2
-17.2
-5.2
-7.2
-9.2
5131E-MCU Wireless-02/09