ADSP-BF50x Blackfin Processor Hardware Reference
8-17
Dynamic Power Management
With an external voltage regulator, this sequence must be reproduced in
the program code by the user. The
PLL_LOCKCNT
register cannot be used in
this case, but the value is still needed for calculating the required delay. A
larger
PLL_LOCKCNT
value may be necessary for changing voltages than
when changing just the PLL frequency. See the processor data sheet for
details.
The processor must enter active mode before the user can access the exter-
nal voltage regulator and program a new voltage level. See the data sheet of
external voltage regulator for information on changing voltage levels. See
the processor data sheet for more information about voltage tolerances
and allowed rates of change.
Reducing the processor’s operating voltage to greatly conserve
power or raising the operating voltage to greatly increase perfor-
mance will probably require significant changes to the operating
voltage level. To ensure predictable behavior the recommended
procedure is to bring the processor to the sleep operating mode
before substantially varying the voltage.
The user must ensure a stable voltage and give the PLL time to re-lock at
the new voltage level. This can be done by running the core in a loop for a
certain amount of time before leaving active mode.
After the voltage has been changed to the new level, the processor can
safely return to any operational mode—so long as the operating parame-
ters, such as core clock frequency (CCLK), are within the limits specified
in the processor data sheet for the new operating voltage level.
Please see
“Changing Voltage Levels” on page 8-39
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-BF50x. The inverted
version of a “power good” signal from the external regulator is fed to the
ADSP-BF50x to indicate that the voltage has reached its programmed
Содержание EZ-KIT Lite ADSP-BF506F
Страница 50: ...Contents l ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 92: ...Development Tools 1 30 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 110: ...Interface Overview 3 12 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 132: ...Unique Information for the ADSP BF50x Processor 4 22 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 236: ...Internal Flash Memory Control Registers 6 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 342: ...Unique Information for the ADSP BF50x Processor 7 106 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 484: ...Unique Information for the ADSP BF50x Processor 10 60 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 493: ...ADSP BF50x Blackfin Processor Hardware Reference 11 9 Core Timer Unique Information for the ADSP BF50x Processor None ...
Страница 494: ...Unique Information for the ADSP BF50x Processor 11 10 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 506: ...Unique Information for the ADSP BF50x Processor 12 12 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 544: ...Unique Information for the ADSP BF50x Processor 13 38 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 650: ...Programming Examples 15 56 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 712: ...Unique Information for the ADSP BF50x Processor 16 62 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 804: ...Programming Examples 17 92 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 972: ...Unique Information for the ADSP BF50x Processor 20 38 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 1194: ...Programming Examples 24 90 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 1256: ...ACM Registers A 50 ADSP BF50x Blackfin Processor Hardware Reference ...
Страница 1264: ...Boundary Scan Architecture B 8 ADSP BF50x Blackfin Processor Hardware Reference ...