em78f644nso28s ELAN Microelectronics Corp, em78f644nso28s Datasheet - Page 157

• Manufacturer Part Number: em78f644nso28s
• Description: Flash Series 8-bit Microcontroller
• Manufacturer: ELAN Microelectronics Corp

Product Specification (V1.0) 05.05.2010
(This specification is subject to change without further notice)
/IRQn
VCC
/RESET
6.13 LVD (Low Voltage Detector) for EM78F648/548N
When an unstable power source condition occurs, such as external power noise
interference or EMS test condition, a violent power vibration is generated. At the
same time, the Vdd becomes unstable as it maybe operating below working voltage.
When the system is operating under low voltage condition, the IC kernel will
automatically keep all register status.
6.13.1 LVD Level Control
LVD property is set at Bank0 R12 (Section 6.3.15). Bits 1 & 0 operation mode is as
follows.
Bits 1~Bit 0 (LVD1~LVD0): Low Voltage Detect level control bits
D
RF
Interrupt sources
CLK
Bit 7
0
P
R
C
ENI/DISI
L
Q
Q
_
Bit 6
Figure 6-25a Interrupt Input Circuit Diagram
0
IOCF
Bit 5
Figure 6-25b Interrupt Backup Diagram
0
Q
Q
_
IOCFRD
RFWR
R
C
P
L
EM78F648/644/642/641/548/544/542/541N
CLK
Bit 4
D
RFRD
0
IOCFWR
LVDEN
ACC
Bit 3
R3
R4
IRQn
IRQm
Interrupt
Bit 2
/LVD
occurs
RETI
8-Bit Microcontroller
LVD1
Bit 1
IOD
ENI/DISI
STACKACC
STACKR3
STACKR4
LVD0
Bit 0
INT
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