Chapter 17 Voltage Regulator (S12VREG3V3V5)
MC9S12XDP512 Data Sheet, Rev. 2.11
744 Freescale Semiconductor

17.3.2.6 Reserved_06

The Reserved_06 is reserved for test purposes.

17.3.2.7 Reserved_07

The Reserved_07 is reserved for test purposes.
17.4 Functional Description

17.4.1 General

Module VREG_3V3 is a voltage regulator, as depicted in Figure 17-1. The regulator functional elements
are the regulator core (REG), a low-voltage detect module (LVD), a control block (CTRL), a power-on
reset module (POR), and a low-voltage reset module (LVR).

17.4.2 Regulator Core (REG)

Respectively its regulator core has two parallel, independent regulation loops (REG1 and REG2) that differ
only in the amount of current that can be delivered.
The regulator is a linear regulator with a bandgap reference when operated in Full Performance Mode. It
acts as a voltage clamp in Reduced Power Mode. All load currents flow from input VDDR to VSS or
VSSPLL. The reference circuits are supplied by VDDA and VSSA.

17.4.2.1 Full Performance Mode

In Full Performance Mode, the output voltage is compared with a reference voltage by an operational
amplifier. The amplified input voltage difference drives the gate of an output transistor.
Module Base + 0x_06
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 17-8. Reserved_06
Module Base + 0x_07
76543210
R00000000
W
Reset 00000000
= Unimplemented or Reserved
Figure 17-9. Reserved_07