Bit microcontroller with infrared module maxq613 – Rainbow Electronics MAXQ613 User Manual
Page 24
16-Bit Microcontroller with Infrared Module
MAXQ613
24 _____________________________________________________________________________________
Table 4. Power-Fail Detection States During Normal Operation
STATE
POWER-FAIL
INTERNAL
REGULATOR
CRYSTAL
OSCILLATOR
SRAM
RETENTION
COMMENTS
A
On
Off
Off
—
V
DD
< V
POR
.
B
On
On
On
—
V
POR
< V
DD
< V
RST
.
Crystal warmup time, t
XTAL_RDY
.
CPU held in reset.
C
On
On
On
—
V
DD
> V
RST
.
CPU normal operation.
D
On
On
On
—
Power drop too short.
Power-fail not detected.
E
On
On
On
—
V
RST
< V
DD
< V
PFW
.
PFI is set when V
RST
< V
DD
< V
PFW
and
maintains this state for at least t
PFW
, at
which time a power-fail interrupt is gener-
ated (if enabled).
CPU continues normal operation.
F
On
(Periodically)
Off
Off
Yes
V
POR
< V
DD
< V
RST
.
Power-fail detected.
CPU goes into reset.
Power-fail monitor turns on periodically.
G
On
On
On
—
V
DD
> V
RST
.
Crystal warmup time, t
XTAL_RDY
.
CPU resumes normal operation from 8000h.
H
On
(Periodically)
Off
Off
Yes
V
POR
< V
DD
< V
RST
.
Power-fail detected.
CPU goes into reset.
Power-fail monitor turns on periodically.
I
Off
Off
Off
—
V
DD
< V
POR
.
Device held in reset. No operation allowed.