
ADSP-BF59x Blackfin Processor Hardware Reference
6-17
Dynamic Power Management
Please see
“Changing Voltage Levels” on page 6-38
for more details on
mode transitions and changing voltage levels.
The
VSTAT
bit in the
PLL_STAT
register can be used to indicate whether
V
DDINT
is stable and ready to use. The
VSTAT
bit works in conjunction
with the
PG
(Power Good) input signal of the ADSP-BF59x. The inverted
version of a "power good" signal from the external regulator is fed to the
ADSP-BF59x to indicate that the voltage has reached its programmed
value. That in turn will set the
VSAT
bit, which should be considered the
end of your "wait" state for the voltage regulator to settle.
Powering Down the Core (Hibernate State)
The external regulator can be signaled to shut off V
DDINT
using the
EXT_WAKE
signal. Writing 0 to the
HIBERNATEB
bit of the
VR_CTL
register,
which disables
CCLK
and
SCLK
, will also make
EXT_WAKE
go low.
EXT_WAKE
will transition high if any wakeup sources occur, which will signal the
external voltage regulator to turn V
DDINT
on again. The wakeup sources
are several user-selectable events, all of which are controlled in the
VR_CTL
register:
• Assertion of the
RESET
pin always exits hibernate state and requires
no modification to
VR_CTL
.
• External GPIO event. Set a GPIO wakeup enable control bit
(
WAKE_EN0
,
WAKE_EN1
,
WAKE_EN2
,
WAKE_EN3
) to enable wakeup on
assertion of a signal on the corresponding pin.
• Pin
EXT_WAKE
is provided to indicate the occurrence of wakeup.
EXT_WAKE
is an output pin, which is a logical OR of the above
wakeup sources, except hardware reset. The pin follows the wakeup
signal of the various wakeup sources.
Summary of Contents for ADSP-BF59x Blackfin
Page 64: ...Development Tools 1 22 ADSP BF59x Blackfin Processor Hardware Reference...
Page 74: ...Processor Specific MMRs 2 10 ADSP BF59x Blackfin Processor Hardware Reference...
Page 244: ...Programming Examples 6 40 ADSP BF59x Blackfin Processor Hardware Reference...
Page 700: ...Programming Examples 16 78 ADSP BF59x Blackfin Processor Hardware Reference...
Page 738: ...Boundary Scan Architecture B 8 ADSP BF59x Blackfin Processor Hardware Reference...