Renesas rl78 Answering Machine User Manual


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RL78/G1A CHAPTER 21 VOLTAGE DETECTOR
21.3.1 Voltage detection register (LVIM)
This register is used to specify whether to enable or disable rewriting the voltage detection level register (LVIS), as well
as to check the LVD output mask status.
This register can be set by a 1-bit or 8-bit memory manipulation instruction.
Reset signal generation clears this register to 00H.
Figure 21-2. Format of Voltage Detection Register (LVIM)
Address: FFFA9H After reset: 00H
Note 1
R/W
Note 2
Symbol <7> 6 5 4 3 2 <1> <0>
LVIM LVISEN
Note 3
0 0 0 0 0 LVIOMSK LVIF
LVISEN
Note 3
Specification of whether to enable or disable rewriting the voltage detection level
register (LVIS)
0 Disabling of rewriting the LVIS register (LVIOMSK = 0 (Mask of LVD output is invalid)
1 Enabling of rewriting the LVIS register (LVIOMSK = 1 (Mask of LVD output is valid)
<R>
<R>
LVIOMSK Mask status flag of LVD output
0 Mask of LVD output is invalid
1 Mask of LVD output is valid
Note 4
<R>
<R>
LVIF Voltage detection flag
0 Supply voltage (VDD) detection voltage (VLVD), or when LVD is off
1 Supply voltage (VDD) < detection voltage (VLVD)
<R>
Notes 1. The reset value changes depending on the reset source.
If the LVIS register is reset by LVD, it is not reset but holds the current value. In other reset, LVISEN is
cleared to 0.
2. Bits 0 and 1 are read-only.
3. LVISEN can only be set in the interrupt & reset mode (option byte LVIMDS1, LVIMDS0 = 1, 0). Do not
change the initial value in other modes.
<R>
4. LVIOMSK bit is only automatically set to “1” when the interrupt & reset mode is selected (option byte
LVIMDS1, LVIMDS0 = 1, 0) and reset or interrupt by LVD is masked.
Period during LVISEN = 1
Waiting period from the time when LVD interrupt is generated until LVD detection voltage becomes
stable
Waiting period from the time when the value of LVILV bit changes until LVD detection voltage becomes
stable
R01UH0305EJ0200 Rev.2.00 756
Jul 04, 2013