5.3.2.1.5 DVS-Capable Regulators
The step-down converters SMPS12 or SMPS123, SMPS45 or SMPS457, SMPS6, and SMPS8 are DVS-capable and have some additional parameters for control. The slew rate of the output voltage during a change in the voltage level is fixed at 2.5 mV/μs. The control for the two different voltage levels (ROOF and FLOOR) with the NSLEEP and ENABLE1 signals is available. The control bits for the output voltage slew rate control the following additional control bits. When the ROOF_FLOOR control is not used, two different voltage levels can be selected with the CMD bit in the SMPSx_FORCE register.
- The output voltage slew rate for achieving new output voltage value is fixed at 2.5 mV/μs.
- The NSLEEP and ENABLE1 pins can be used for roof-floor control of SMPS. For roof-floor operation sets the SMPSx_CTRL.ROOF_FLOOR_EN register, and assign SMPS to NSLEEP and ENABLE1 in the NSLEEP_SMPS_ASSIGN and ENABLE1_SMPS_ASSIGN registers. When the controlling pin is active, the SMPS output value is defined by the SMPSx_VOLTAGE register. When the controlling pin is not active, the SMPS output value is defined by the SMPSx_FORCE register.
- Set the second value for the output voltage with the SMPSx_FORCE.VSEL register. A value of 0x0 disables the SMPS (OFF).
- Select which register, SMPSx_VOLTAGE or SMPSx_FORCE, to use with the SMPSx_FORCE.CMD bit. The default is the voltage setting of SMPSx_VOLTAGE. For the CMD bit to work, ensure that SMPSx_CTRL.ROOF_FLOOR_EN = 0.
Figure 5-5 and Figure 5-4 show the SMPS controls for DVS.