Datasheet

3.4 Bandgap reference
This device includes an on-chip bandgap reference (≈1.2V) connected to ADC channel
and ACMP. The bandgap reference voltage will not drop under the full operating voltage
even when the operating voltage is falling. This reference voltage acts as an ideal
reference voltage for accurate measurements.
3.5 Power management control bits and registers
PMC memory map
Absolute
address
(hex)
Register name
Width
(in bits)
Access Reset value
Section/
page
3040
System Power Management Status and Control 1 Register
(PMC_SPMSC1)
8 R/W 1Ch 3.5.1/56
3041
System Power Management Status and Control 2 Register
(PMC_SPMSC2)
8 R/W 00h 3.5.2/58
3.5.1 System Power Management Status and Control 1 Register
(PMC_SPMSC1)
This high page register contains status and control bits to support the low-voltage
detection function, and to enable the bandgap voltage reference for use by the ADC
module. This register should be written during the user's reset initialization program to
set the desired controls, even if the desired settings are the same as the reset settings.
Address: 3040h base + 0h offset = 3040h
Bit 7 6 5 4 3 2 1 0
Read LVWF 0
LVWIE LVDRE LVDSE LVDE BGBDS BGBE
Write LVWACK
Reset
0 0 0 1 1 1 0 0
PMC_SPMSC1 field descriptions
Field Description
7
LVWF
Low-Voltage Warning Flag
The LVWF bit indicates the low-voltage warning status.
Table continues on the next page...
Bandgap reference
MC9S08PA60 Reference Manual, Rev. 1, 9/2012
56 Freescale Semiconductor, Inc.