Texas Instruments OMAP36 Series, Technical Reference Manual

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PRCM Functional Description
Table 3-82. VDD2 Voltage Domain Dependencies (continued)
VDD2 Power DPLL State sys_clk Software VDD1 VDD3 VDD4 VDD5
Domain Domains Control
State State
Retenti Software All DPLLs are in No longer AUTO_SLEE ON or ON or ON or Retention
on controlled Stop mode. required P = 0 retention Overdriven retention
power AUTO_RET =
domains of 1
VDD1 are in AUTO_OFF =
inactive, 0
retention or
off state and
of VDD2 are
in retention or
off state.
Off Software All DPLLs are in No longer AUTO_SLEE Off SLEEP Off Off
controllable Stop mode. required P = 0
power AUTO_RET =
domains of 0
VDD1 and AUTO_OFF =
VDD2 are in 1
off state.
NOTE:
• In voltage domain SLEEP state, the current load decreases because of reduced activity
level; however, the voltage level remains that of on state.
• In voltage domain overdriven state, the domain voltage is raised above the nominal
operating voltage to boost performance; however, power consumption also increases.
• AUTO_SLEEP, AUTO_RET and AUTO_OFF, in the Software Control column, refer to
the
PRM_VOLTCTRL [0] AUTO_SLEEP, PRM_VOLTCTRL [1] AUTO_RET and
PRM_VOLTCTRL [2] AUTO_OFF bits.
Table 3-83. Remaining Voltage Domain Dependencies
Voltage Condition
VDDS
External memory I/Os
VDDADAC
VDDPLL
VDDPLL_PER
CSIB No dependency with other device voltages
DSI
CSIPHY2
SIM
MMC_VDDS
3.5.6.4 Voltage-Control Architecture
The PRM is split over several blocks that manage the different voltage sources.
• VDD1 and VDD2 voltages are managed by multiple control sources:
– Automatic voltage adjustment (for optimal performance at an OPP) and software-requested voltage
scaling (for OPP change) are managed by two SmartReflex voltage control modules connected to
two voltage processor modules. They generate voltage-adjustment commands based on the
desired and current performance levels of the device. These commands are sent to the external
power IC through a voltage controller and a dedicated I
2
C interface.
– Direct software control of VDD1 and VDD2 is also possible by writing to the registers of the voltage
controller, which then sends the voltage commands to the power IC through the dedicated I
2
C
377 SWPU177N – December 2009 – Revised November 2010 Power, Reset, and Clock Management
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