upd78f0103 Renesas Electronics Corporation., upd78f0103 Datasheet - Page 328

• Manufacturer Part Number: upd78f0103
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

(1) Low-voltage detection register (LVIM)
328
Address: FFBEH
Symbol
This register sets low-voltage detection and the operation mode.
This register can be set by a 1-bit or 8-bit memory manipulation instruction.
RESET input clears LVIM to 00H.
LVIM
Notes 1.
Caution To stop LVI, follow either of the procedures below.
LVION
LVIE
LVIMD
LVIF
LVION
<7>
Notes 2, 4, 5
0
1
0
1
0
1
0
1
Notes 2, 3
Note 6
2.
3.
4.
5.
6.
Note 2
After reset: 00H
• When using 8-bit memory manipulation instruction: Write 00H to LVIM.
• When using 1-bit memory manipulation instruction: Clear LVION to 0 first and then
Bit 0 is read-only.
LVION, LVIE, and LVIMD are cleared to 0 in the case of a reset other than an LVI reset.
These are not cleared to 0 in the case of an LVI reset.
When LVION is set to 1, operation of the comparator in the LVI circuit is started. Use
software to instigate a wait of at least 0.2 ms from when LVION is set to 1 until the voltage is
confirmed at LVIF.
If “POC cannot be used” is selected by a mask option, wait for 2 ms or more by software from
when LVIE is set to 1 until LVION is set to 1.
If “POC used” is selected by a mask option, setting of LVIE is invalid because the reference
voltage generator in the LVI circuit always operates.
The value of LVIF is output as the interrupt request signal INTLVI when LVION = 1 and
LVIMD = 0.
Disables operation
Enables operation
Disables operation
Enables operation
Generates interrupt signal when supply voltage (V
Generates internal reset signal when supply voltage (V
Supply voltage (V
Supply voltage (V
Figure 19-2. Format of Low-Voltage Detection Register (LVIM)
6
0
CHAPTER 19 LOW-VOLTAGE DETECTOR
R/W
DD
DD
5
0
) > detection voltage (V
) < detection voltage (V
Note 1
Low-voltage detection operation mode selection
User’s Manual U15836EJ5V0UD
Enables low-voltage detection operation
Specifies reference voltage generator
LVIE
<4>
Low-voltage detection flag
LVI
LVI
3
0
), or when operation is disabled
)
DD
) < detection voltage (V
DD
2
0
) < detection voltage (V
clear LVIE to 0.
LVIMD
<1>
LVI
)
LVI
LVIF
<0>
)