AT86RF231 datasheet(49/180 Pages) ATMEL

49 / 180 page

8111A–AVR–05/08

AT86RF231

7.2.1

State Control

The Extended Operating Mode states RX_AACK and TX_ARET are controlled via register bits

TRX_CMD (register 0x02, TRX_STATE), which receives the state transition commands. The

states are entered from TRX_OFF or PLL_ON state as illustrated by Figure 7-8 on page 48. The

completion of each state change command shall always be confirmed by reading the register

0x01 (TRX_STATUS).

RX_AACK - Receive with Automatic ACK

A state transition to RX_AACK_ON from PLL_ON or TRX_OFF is initiated by writing the com-

mand RX_AACK_ON to the register bits TRX_CMD. The state change can be confirmed by

reading register 0x01 (TRX_STATUS), those changes to RX_AACK_ON or BUSY_RX_AACK

on success. The latter one is returned if a frame is currently about being received.

The RX_AACK state is left by writing command TRX_OFF or PLL_ON to the register bits

TRX_CMD. If the AT86RF231 is within a frame receive or acknowledgment procedure

(BUSY_RX_AACK) the state change is executed after finish. Alternatively, the commands

FORCE_TRX_OFF or FORCE_PLL_ON can be used to cancel the RX_AACK transaction and

change into radio transceiver state TRX_OFF or PLL_ON, respectively.

TX_ARET - Transmit with Automatic Retry and CSMA-CA Retry

Similarly, a state transition to TX_ARET_ON from PLL_ON or TRX_OFF is initiated by writing

command TX_ARET_ON to register bits TRX_CMD. The radio transceiver is in the

TX_ARET_ON state after TRX_STATUS (register 0x01) changes to TX_ARET_ON. The

TX_ARET transaction is started with a rising edge of pin 11 (SLP_TR) or writing the command

TX_START to register bits TRX_CMD.

The TX_ARET state is left by writing the command TRX_OFF or PLL_ON to the register bits

TRX_CMD. If the AT86RF231 is within a CSMA-CA, a frame-transmit or an acknowledgment

procedure (BUSY_TX_ARET) the state change is executed after finish. Alternatively the com-

mand FORCE_TRX_OFF or FORCE_PLL_ON can be used to instantly terminate the TX_ARET

transaction and change into radio transceiver state TRX_OFF or PLL_ON, respectively.

Note

• A state change request from TRX_OFF to RX_AACK_ON or TX_ARET_ON internally

passes the state PLL_ON to initiate the radio transceiver. Thus the readiness to receive or

transmit data is delayed accordingly. It is recommended to use interrupt IRQ_0 (PLL_LOCK)

as an indicator.

AT86RF231 Datasheet(PDF) 49 Page - ATMEL Corporation