MC9S08QG8_09 Datasheet, PDF (76/314 Pages) Freescale Semiconductor, Inc – HCS08 Microcontrollers

Chapter 5 Resets, Interrupts, and General System Control
5.8.8 System Power Management Status and Control 1 Register
(SPMSC1)
This high page register contains status and control bits to support the low voltage detect function and to
enable the bandgap voltage reference for use by the ADC module. To configure the low voltage detect trip
voltage, see Table 5-14 for the LVDV bit description in SPMSC3.
1
7
6
5
4
3
2
1
R LVDF
0
0
LVDIE
LVDRE²
LVDSE
LVDE ²
W
LVDACK
Reset:
0
0
0
1
1
1
0
= Unimplemented or Reserved
Figure 5-10. System Power Management Status and Control 1 Register (SPMSC1)
1 _{Bit 1 is a reserved bit that must always be written to 0.}
2 _{This bit can be written only one time after reset. Additional writes are ignored.}
Table 5-12. SPMSC1 Register Field Descriptions
0
BGBE
0
Field
Description
7
LVDF
6
LVDACK
5
LVDIE
4
LVDRE
3
LVDSE
2
LVDE
0
BGBE
Low-Voltage Detect Flag — Provided LVDE = 1, this read-only status bit indicates a low-voltage detect event.
Low-Voltage Detect Acknowledge — This write-only bit is used to acknowledge low voltage detection errors
(write 1 to clear LVDF). Reads always return 0.
Low-Voltage Detect Interrupt Enable — This bit enables hardware interrupt requests for LVDF.
0 Hardware interrupt disabled (use polling).
1 Request a hardware interrupt when LVDF = 1.
Low-Voltage Detect Reset Enable — This write-once bit enables LVDF events to generate a hardware reset
(provided LVDE = 1).
0 LVDF does not generate hardware resets.
1 Force an MCU reset when LVDF = 1.
Low-Voltage Detect Stop Enable — Provided LVDE = 1, this read/write bit determines whether the low-voltage
detect function operates when the MCU is in stop mode.
0 Low-voltage detect disabled during stop mode.
1 Low-voltage detect enabled during stop mode.
Low-Voltage Detect Enable — This write-once bit enables low-voltage detect logic and qualifies the operation
of other bits in this register.
0 LVD logic disabled.
1 LVD logic enabled.
Bandgap Buffer Enable — This bit enables an internal buffer for the bandgap voltage reference for use by the
ADC module on one of its internal channels or as a voltage reference for ACMP module.
0 Bandgap buffer disabled.
1 Bandgap buffer enabled.
MC9S08QG8 and MC9S08QG4 Data Sheet, Rev. 5
74
Freescale Semiconductor