Renesas H8/38024 Series, Hardware Manual

Page: 455 / 661

Rev. 6.00, 08/04, page 425 of 628
14.1.3 Pin Description
The pins of the power-on reset circuit and low-voltage detection circuit are listed in table 14.1.
Table 14.1 Pin Description
Pin Symbol I/O Function
Low-voltage detection circuit
reference voltage input pin Vref Input Reference voltage input for low-
voltage detection circuit
Low-voltage detection circuit power
supply drop detection voltage input
pin extD Input Power supply drop detection voltage
input pin for low-voltage detection
circuit
Low-voltage detection circuit power
supply rise detection voltage input
pin extU Input Power supply rise detection voltage
input pin for low-voltage detection
circuit
14.1.4 Register Descriptions
The registers of the power-on reset circuit and low-voltage detection circuit are listed in table 14.2.
Table 14.2 Register Descriptions
Name Symbol R/W Initial Value Address
Low-voltage detection control register LVDCR R/W H'00 H'FF86
Low-voltage detection status register LVDSR R/W H'00 H'FF87
Low-voltage detection counter LVDCNT R H'00 H'FFC3
14.2 Individual Register Descriptions
14.2.1 Low-Voltage Detection Control Register (LVDCR)
Bit 7 6 5 4 3 2 1 0
LVDE —
VINTDSEL VINTUSEL
LVDSEL LVDRE LVDDE LVDUE
Initial value 0
*
0 0 0 0
*
0
*
0 0
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
Note: * These bits are not initialized by resets trigged by LVDR. They are initialized by power-on
resets and watchdog timer resets.
LVDCR is an 8-bit read/write register. It is used to control whether or not the low-voltage
detection circuit is used, settings for external input of power supply rise and drop detection