CMOSTEK CMT2300A, Руководство пользователя

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CMT2300A
Rev 1.0 | Page31/46
www.cmostek.com
IDLE
0000
SLEEP
0001
STBY
0010
TFS
0100
RX
0101
RFS
0011
TX
0110
go_stby
go_tx
go_stby
go_sleep
go_stby
go_rx
go_switch
go_switch
go
_s
tb
y
go
_t
fs
go
_st
by
go
_rfs
go_tfs go_tx
go_rfs go_rx
go_tfs
go_sleep
go_rfs
go_sleep
go_sleep
go_tx
go_sleep
go_rx
Power up
Figure 16. State Switch Diagram
 SLEEP State
The chip power consumption is the lowest in SLEEP state, and almost all the modules are turned off. SPI is open, the registers of
the configuration bank and control bank 1 will be saved, and the contents filled in the FIFO before will remain unchanged.
However, the user cannot operate the FIFO and cannot change the contents of the register. If the user opens the wake-up
function, the LFOSC and the sleep counter will turn on and start working. The time required to switch from IDLE to SLEEP is the
power up time. Switch from other state to SLEEP will be completed immediately.
 STBY State
In STBY state, the crystal is turned on, the LDO of the digital circuit will also be turned on, the current will be slightly increased,
and the FIFO can be operated. The user can choose whether to output CLKO (system clock) to PIN. Because the crystal and
LDO is turned on, compared to the SLEEP, the time switching from the STBY to transmitting or receiving will be relatively short.
Switching from SLEEP to STBY will be completed after the crystal is turned on and settled. Switching from other state to STBY
will be completed immediately.
 RFS State
RFS is a transition state before switching to RX. Except that the receiver RF module is off, the other modules are turned on, and
the current will be larger than STBY. Because PLL has been locked in the RX frequency, RFS cannot switch to TX. Switching
from STBY to RFS probably requires PLL calibration and stability time of 350us. Switching from SLEEP to RFS needs to add the
crystal start-up and stability time. Switching from other state to RFS will be completed immediately.
 TFS State
TFS is a transition state before switching to TX. Except that the transmitter RF module is off, the other modules are turned on,
and the current will be larger than STBY. Because PLL has been locked in the TX frequency, TFS cannot switch to RX. Switching
from STBY to TFS probably requires PLL calibration and stability time of 350us. Switching from SLEEP to TFS needs to add the