Clock Generation
15-20
15.2.8 Low-Power Mode
The OMAP5910 LOW_PWR I/O is an active-high request for LOW_PWR
mode (see Figure 15–9). It automatically requests external regulators to go to
standby (low-power mode) or to lower the VDD core voltage during deep sleep
mode. A software request, through bit 1 of the power control register
(POWER_CTRL_REG), is available for debug and future support of the low
voltage operational mode.
The LOW_PWR signal is multiplexed on the MPUIO5 ball. To get it on this ball,
you must set bits (14:12) of the FUNC_MUX_CTRL_7 register to 001.
Figure 15–9. Low-Voltage Mode
Low_pwr
1.5 V
Awake...big sleep
Deep sleep
Analog
wait
timer
Big sleep...awake
1.1 V
ULPD state
LOW_PWR
V
DD
ULPD analog wait state timer delays
deep sleep to big sleep transition
while regulator changes from
1.1 ~1.5 V.
OMAP5910
ULPD:
If(’deep sleep state’ or SW
low_pwr_req)
and (SW low_pwr_en)
Then
low_pwr=1
else low_pwr=0
Power IC
1.5 V ~1.1 V
Select
V
DD
regulator
V
DD