AT86RF230_09 ATMEL [ATMEL Corporation], AT86RF230_09 Datasheet - Page 24

• 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]

7.1.2.7 BUSY_TX – Transmit State
7.1.3 Interrupt Handling in Basic Operating Mode
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AT86RF230
reception of a frame is indicated to the microcontroller by a RX_START interrupt. CLKM
is turned on again, and the radio transceiver enters the BUSY_RX state (see section
6.4, Figure 6-16).
The end of the transaction is indicated to the microcontroller by a TRX_END interrupt.
After the transaction has been completed, the radio transceiver enters the RX_ON
state. The radio transceiver only reenters the RX_ON_NOCLK state, when the next
rising edge at pin SLP_TR occurs.
If the radio transceiver is in the RX_ON_NOCLK state, and the SLP_TR pin is reset to
logic low, it enters the RX_ON state, and it starts to supply clock on the CLKM pin
again.
In states RX_ON_NOCLK and RX_ON, the current consumption is about the same,
because only the CLKM output is switched off in state RX_ON_NOCLK.
A transmission can only be started in state PLL_ON. There are two ways to start a
transmission:
• Rising edge of SLP_TR
• TX_START command to register 0x02 (TRX_STATE).
Either of these causes the AT86RF230 to enter the BUSY_TX state.
During the transition to BUSY_TX state, the PLL frequency shifts to the transmit
frequency. Transmission of the first data chip of the preamble starts after 16 µs to allow
PLL settling and PA ramping, see Figure 7-2. After transmission of the preamble and
the SFD, the Frame Buffer content is transmitted.
The last two bytes to be transmitted are the FCS (see Figure 8-2). The radio transceiver
can be configured to autonomously compute the FCS bytes and append it to the
transmit data. The register bit TX_AUTO_CRC_ON in register 0x05 (PHY_TX_PWR)
needs to be set to 1 to enable this feature. For further details refer to section 8.2.When
the frame transmission is completed, the radio transceiver automatically turns off the
power amplifier, generates a TRX_END interrupt and returns to PLL_ON state.
Note that in case the PHR indicates a frame length of zero, the transmission is aborted.
All interrupts of the AT86RF230 (see Table 6-8) are supported during operation in Basic
Operating Mode.
Two interrupts are used to support RX and TX operation of the radio transceiver. On
receive the RX_START interrupt indicates the detection of a valid SFD. The TRX_END
interrupt indicates the completion of the frame reception or frame transmission.
Figure 7-2 shows a receive/transmit transaction and the related interrupt events in
Basic Operating Mode. One device is assumed to operate as transmitter (device 1), the
second one as receiver (device 2). Processing delays are typical values.
5131E-MCU Wireless-02/09