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PRCM Use Cases and Tips
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The step size of the SMPS for VDD1 and VDD2 is 12 mV. The minimum and maximum voltage steps
are configured accordingly.
PRCM.PRM_VPn_VSTEPMIN[7:0] VSTEPMIN
Depends on the characteristics of the SMPS
PRCM.PRM_VPn_VSTEPMAX[7:0]
VSTEPMAX
Configure the acknowledge time-out delay, initial voltage values, and slew rates for the SMPS.
PRCM.PRM_VPn_VLIMITTO[15:0] TIMEOUT
Maximum amount of time to wait for the command
acknowledge from the SMPS
[15:8] INITVOLTAGE
0x3C
1.26 V (VDD1 OPP130)
[15:8] INITVOLTAGE
0x2C
1.15 V (VDD2 OPP100)
PRCM.PRM_VPn_CONFIG[2] INITVDD
0x1
Asserts the initial voltage into the voltage processor
FSM
PRCM.PRM_VPn_VSTEPMIN[23:8] SMPSWAITTIMEMIN
Depends on the characteristics of the SMPS
PRCM.PRM_VPn_VSTEPMAX[23:8] SMPSWAITTIMEMAX
3. Initialize the voltage controller.
Set the slave address (register group address) for the TWL5030 power IC SmartReflex register group
(0x12). Because only one power IC is used, SA1 is not configured.
[6:0] SA0
0x12
Register group ID5 of TWL5030
Set the voltage data configuration register address to that of the VDD1_SR_CONTROL and
VDD2_SR_CONTROL registers of the TWL5030.
[7:0] VOLRA0
0x0
VDD1_SR_CONTROL register address
[23:16] VOLRA1
0x1
VDD2_SR_CONTROL register address
By default, the voltage controller pointers are configured to use the corresponding slave and register
addresses assigned earlier.
By default, the I2C4 is configured in HS mode. Because the TWL5030 supports HS mode, there is no
need to switch to F/S mode. Because the voltage processor transmits the individual voltage commands
byte-by-byte, the repeated start operation is not necessary. Therefore, this mode is disabled.
[2:0] MCODE
-
A master code for I
2
C HS preamble
[4] SREN
0x0
Disable the repeated start operation.
4. Enable the modules.
Enable the voltage processor and SmartReflex modules.
PRCM.PRM_VPn_CONFIG[0] VPENABLE
0x1
Enable the voltage processor module.
[11] SR_EN
0x1
Enable the SmartReflex module.
The valid interrupt of the MPU signals that the voltage has stabilized to within the limits.
452
Power, Reset, and Clock Management
SWPU177N – December 2009 – Revised November 2010
Copyright © 2009–2010, Texas Instruments Incorporated