Advance Information MC68HC908MR16/MC68HC908MR32 — Rev. 4.0
338 Low-Voltage Inhibit (LVI) MOTOROLA
Low-Voltage Inhibit (LVI)
18.4.4 LVI Trip Selection
The TRPSEL bit allows the user to chose between 5 percent and
10 percent tolerance when monitoring the supply voltage. The
10 percent option is enabled out of reset. Writing a logic 1 to TRPSEL
will enable 5 percent option.
NOTE: The microcontroller is guaranteed to operate at a minimum supply
voltage. The trip point (VLVR1 or VLVR2) may be lower than this.
See 22.6 DC Electrical Characteristics (VDD = 5.0 Vdc

±

10%).
18.5 LVI Status and Control Register
The LVI status register (LVISCR) flags VDD voltages below the VLVRX
level.
LVIOUT — LVI Output Bit
This read-only flag becomes set when the VDD voltage falls below the
VLVRX voltage for 32 to 40 CGMXCLK cycles. See Table 18-1. Reset
clears the LVIOUT bit.
Address: $FE0F
Bit 7654321Bit 0
Read: LVIOUT 0 TRPSEL 00000
Write:RR RRRRR
Reset:00000000
R= Reserved
Figure 18-3. LVI Status and Control Register (LVISCR)