HD6433694 Datasheet, PDF (310/432 Pages) Renesas Technology Corp – 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Tiny Series

Procedures for Clearing Settings when Using LVDR and LVDI:
To operate or release the low-voltage detection circuit normally, follow the procedure described
below. Figure 18.5 shows the timing for the operation and release of the low-voltage detection
circuit.
1. To operate the low-voltage detection circuit, set the LVDE bit in LVDCR to 1.
2. Wait for 50 µs (t_LVDON) until the reference voltage and the low-voltage-detection power supply
have stabilized by a software timer, etc. Then, clear the LVDDF and LVDUF bits in LVDSR
to 0 and set the LVDRE, LVDDE, and LVDUE bits in LVDCR to 1, as required.
3. To release the low-voltage detection circuit, start by clearing all of the LVDRE, LVDDE, and
LVDUE bits to 0. Then clear the LVDE bit to 0. The LVDE bit must not be cleared to 0 at the
same timing as the LVDRE, LVDDE, and LVDUE bits because incorrect operation may occur.
LVDE
LVDRE
LVDDE
LVDUE
tLVDON
Figure 18.5 Timing for Operation/Release of Low-Voltage Detection Circuit
Rev. 4.00, 03/04, page 282 of 400