Renesas RL78 Series User Manual page 639

RL78/G1D
(3) STANDBY_RF mode
On entering this mode, operation of the oscillating circuit for the RF base clock and the DC-DC converter is
possible. After this mode is entered, the wait time for oscillation stabilization and DC-DC converter output
stabilization is required. Accordingly, during that period, transition to another mode is prohibited. Software should
control the period of waiting for oscillation to become stable. The wait time becomes as follows:
Oscillation stabilization wait time: At least 550 µs + α (where α depends on the external oscillation circuit)
DC-DC converter output stabilization wait time: At least 250 µs
This mode can be entered from the following two states.
● In RESET_RF mode, when the CE_RF internal pin input changes from low to high, this mode is entered.
● In IDLE_RF mode, when the RESET_RF internal pin input changes from high to low, this mode is entered.
(4) IDLE_RF mode
Idle state waiting for a packet transmission/reception event to occur. When an event occurs, the analog circuit is
activated and so a transition is made to SETUP_RF mode. After packet transmission or reception has been
completed, a transition is made to this mode and idle state is entered again.
This mode can be entered from the following five states.
● In STANDBY_RF mode, when the RESET_RF internal pin input changes from low to high after waiting for
oscillation stabilization, this mode is entered.
● In SLEEP_RF mode, after a SLEEP_RF mode release source is generated, this mode is entered.
● In RF transmission mode, after packet transmission has been completed, this mode is entered.
● In RF reception mode, after packet reception has been completed, this mode is entered.
● In DEEP_SLEEP mode, after a DEEP_SLEEP mode release source is generated, this mode is entered.
(5) DEEP_SLEEP mode
In this mode, the supply of power to circuits other than the RF slow clock and the wakeup circuit used to wake up
from DEEP_SLEEP mode is stopped. Therefore, waking up from this mode to enter IDLE_RF mode can proceed
after waiting for the oscillation of the RF base clock and the output of the DC-DC converter to become stable. This
mode consumes less power than SLEEP_RF mode but it takes more time to wake up from this mode than from
SLEEP_RF mode.
This mode can be entered with the following method.
● When a command to enter DEEP_SLEEP mode is issued with the CE_RF internal pin input changing from high
to low, this mode is entered.
(6) SLEEP_RF mode
In this mode, operation of circuits other than the RF slow clock and the wakeup circuit used to wake up from
SLEEP_RF mode is stopped. The RF unit consumes more power in this mode than in DEEP_SLEEP mode but it
takes less time to wake up from this mode than it does from DEEP_SLEEP mode.
This mode can be entered with the following method.
● When a command to enter SLEEP_RF mode is issued, this mode is entered
R01UH0515EJ0120 Rev.1.20
Dec 16, 2016
CHAPTER 15 RF TRANSCEIVER
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