Set INTIVDD bit
of the voltage processor
End
Set new operating frequency
Start
Set the initial voltage parameter
of the voltage processor
corresponding to target OPP
Disable SmartReflex module
1
.
D
is
a
b
le
m
o
d
u
le
s
Disable voltage processor
module
Set FORCEUPDATE bit
of the voltage processor
2.
F
orc
e
S
M
P
S
v
o
lt
a
g
e
u
p
d
a
te
Is
frequency?
No
target OPP frequency < current OPP
Yes
Is
frequency?
target OPP frequency > current OPP
No
Yes
prcm-UC-015
Set new operating frequency
Frequency scaling when
target OPP
frequency
is less than
current OPP
frequency
Frequency scaling when
target OPP
frequency
is greater than
current OPP
frequency
Public Version
www.ti.com
PRCM Basic Programming Model
Figure 3-100. Voltage Processor - OPP Change Flow Chart
When switching from the current OPP to a target OPP, if the clock frequency of the target OPP is less
than that of current OPP, the DPLL is first switched to the lower frequency of target OPP, and only then
the voltage scaling is initiated. However, if the clock frequency of the target OPP is greater than that of
current OPP, voltage scaling is initiated before frequency scaling (see
OPP voltage-switching-complete is detected by the OPPCHANGEDONE interrupt from the voltage
processor to the MPU. For this, the corresponding MPU interrupt must be unmasked.
NOTE:
In the following steps, VPn refers to VP1 if VDD1 OPP is changed, and to VP2 if VDD2
OPP is changed.
1. Disable the modules.
445
SWPU177N – December 2009 – Revised November 2010
Power, Reset, and Clock Management
Copyright © 2009–2010, Texas Instruments Incorporated