14.2.1.4.5 Reset Procedure

The radio transceiver reset procedure is shown in the figure below.

Figure 14-25. Reset Procedure
  1. Timing figure tTR13 refers to State Transition Timing table, t10 refers to the Digital Interface Timing Characteristics.

/RST = L sets all registers to their default values. Exceptions are the CLKM_CTRL bits in the TRX_CTRL_0 register (TRX_CTRL_0.CLKM_CTRL). After releasing the reset pin 8 (/RST) = H, the wake-up sequence including an FTN calibration cycle is performed. After that, the TRX_OFF state is entered.

The above figure illustrates the reset procedure once P_ON state was left and the radio transceiver was not in SLEEP state.

The reset procedure is identical for all originating radio transceiver states except of states P_ON and SLEEP. Instead, the procedures described in the Basic Operation State Control and Basic Operationg Mode Description sections must be followed to enter the TRX_OFF state.

If the radio transceiver was in SLEEP state, the XOSC and DVREG are enabled before entering TRX_OFF state.

If register bits TRX_STATUS indicates STATE_TRANSITION_IN_PROGRESS during system initialization until the AT86RF212B reaches TRX_OFF state, do not try to initiate a further state change while the radio transceiver is in this state.

Note:
  1. The reset impulse should have a minimum length t10 = 625ns as specified in the Digital Interface Timing Characteristics.
  2. An access to the device should not occur earlier than t11 ≥ 625ns after releasing the /RST pin; refer the Digital Interface Timing Characteristics.
  3. A reset overrides an SPI command request that might have been queued.