SN8P2711A
8-Bit Micro-Controller
SONiX TECHNOLOGY CO., LTD
Page 42
Version 0.1
LVD reset:
VDD
VSS
System Normal Run
System Stop
LVD Detect Voltage
Power On
Delay Time
Power
System Status
Power is below LVD Detect
Voltage and System Reset.
The LVD (low voltage detector) is built-in Sonix 8-bit MCU to be brown out reset protection. When the VDD drops and
is below LVD detect voltage, the LVD would be triggered, and the system is reset. The LVD detect level is different by
each MCU. The LVD voltage level is a point of voltage and not easy to cover all dead-band range. Using LVD to
improve brown out reset is depend on application requirement and environment. If the power variation is very deep,
violent and trigger the LVD, the LVD can be the protection. If the power variation can touch the LVD detect level and
make system work error, the LVD can’t be the protection and need to other reset methods. More detail LVD information
is in the electrical characteristic section.
The LVD is three levels design (2.0V/2.4V/3.6V) and controlled by LVD code option. The 2.0V LVD is always enable for
power on reset and Brown Out reset. The 2.4V LVD includes LVD reset function and flag function to indicate VDD
status function. The 3.6V includes flag function to indicate VDD status. LVD flag function can be an
easy low battery
detector
. LVD24, LVD36 flags indicate VDD voltage level. For low battery detect application, only checking LVD24,
LVD36 status to be battery status. This is a cheap and easy solution.
086H
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PFLAG
NT0 NPD
LVD36
LVD24 -
C DC Z
Read/Write
R/W R/W R
R
- R/W R/W R/W
After
reset
- - 0 0 - 0 0 0
Bit 5
LVD36:
LVD 3.6V operating flag and only support LVD code option is LVD_H.
0 = Inactive (VDD > 3.6V).
1 = Active (VDD <= 3.6V).
Bit 4
LVD24:
LVD 2.4V operating flag and only support LVD code option is LVD_M.
0 = Inactive (VDD > 2.4V).
1 = Active (VDD <= 2.4V).