STW4810_0709 Datasheet, PDF (19/79 Pages) STMicroelectronics – Power management for multimedia processors

Functional description
STw4810
4.2.2
POWER OFF / VDDOK
● In case of VDDOK falling edge due to under voltage on VCORE or VIO_VMEM
detected, or ‘it_twarn’ bit set to “1” (Table 18), then multimedia processor is reset
(PORn low during a minimum time of 312.5 µs) and restarted with no time-out. (see
Figure 5). In case of VDDOK falling edge because PWREN balls equals “0”, there is no
reset (PORn still high).
● In case of PON falling edge (STw4810 switched off from modem) multimedia processor
is also reset with no time-out. We consider that clean switch off between modem and
multimedia processor is done by software directly.
Figure 5. VDDOK block diagram
vcore_monitor
PWREN
vio_monitor
Digital block
&
VDDOK
&
it_twarn
mask_twarn
register reset after
read operation
or PON falling edge
or PORN_VBAT.
Reg status
Under voltage detection
VDDOK
Operating voltage threshold value reached
PORn
312.5 µs
(10* 32 Khz)
4.2.3
Sleep mode
STw4810 goes into sleep mode by different ways.
Whether VCORE, VIO_VMEM and VAUX are programmed to sleep mode or not is indicated
in Table 27.
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