hd64338023s Renesas Electronics Corporation., hd64338023s Datasheet - Page 484

• Manufacturer Part Number: hd64338023s
• Description: Renesas 8-bit Single-chip Microcomputer Super Low Power Series
• Manufacturer: Renesas Electronics Corporation.

Section 14 Power-On Reset and Low-Voltage Detection Circuits (H8/38124 Group Only)
14.2.3
LVDCNT is a read-only 8-bit up-counter. Counting begins when 1 is written to LVDE. The
counter increments using φ/4 as the clock source until it overflows by switching from H'FF to
H'00, at which time the OVF bit in the LVDSR register is set to 1, indicating that the on-chip
reference voltage generator has stabilized. If the LVD function is used, it is necessary to stand by
until the counter has overflowed. The initial value of LVDCNT is H'00.
14.2.4
CKSTPR2 is an 8-bit read/write register. It is used to control the module’s module standby mode.
Only the bits relevant to the LVD function are described in this section. Refer to the sections on
the other modules for information about the other bits.
Bit 7—LVD Module Standby Control (LVDCKSTP)
This bit is used to control setting of the LVD function to module standby status and cancellation of
that status.
Bit 7
LVDCKSTP
0
1
Note: This bit is implemented on the H8/38124 Group only. On other products it is always read as
Rev. 7.00 Mar 10, 2005 page 442 of 652
REJ09B0042-0700
Bit
Initial value
Read/Write
Bit
Initial value
Read/Write
1 and cannot be written to.
Low-Voltage Detection Counter (LVDCNT)
Clock Stop Register 2 (CKSTPR2)
LVDCKSTP
Description
Sets LVD to module standby status
Cancels LVD module standby status
CNT7
R/W
R
7
0
7
1
CNT6
—
—
R
6
0
6
1
CNT5
—
—
R
5
0
5
1
PW2CKSTP AECKSTP
CNT4
R/W
R
4
0
4
1
CNT3
R/W
R
3
0
3
1
WDCKSTP PW1CKSTP LDCKSTP
CNT2
R/W
R
2
0
2
1
CNT1
R/W
R
1
0
1
1
(initial value)
CNT0
R/W
R
0
0
0
1