PRELIMINARY ISD1700 SERIES
Publication Release Date: Nov 6, 2008
- 25 -
Revision 1.31
o
As
ERASE
is maintained Low continuously, the device will erase all messages
and play SE4 with LED flashing simultaneously upon completion.
SE3
SE4
H
interrupted during such process, the circular memory architecture will be destroyed. As a
o
During this process, the blinking periods of twice, three times and four times are
limited by the recorded durations of SE2, SE3 and SE4 (T
SE2
,T
and T
)
respectively.
owever, it is vital to maintain the power supply On during the erase process. If power is
result, next time when a push button operation starts, the LED will blink seven times, which
indicates that something abnormal has occurred, and the device will fail to perform the
requested operation. Under such scenario, the only way to recover the chip to a proper state
is to perform a Global Erase operation.
Triggering
ERASE
for individual erase during a record or forward operation is an illegal
operation and will be ignored. However
ERASE
, triggering
for an individual erase operation
In general, when a push button switch is used on this control, a 0.1
μ
F capacitor is typically
e
during playback will delete the current played message, if it is the first or last one.
Figure 8.1: Global Erase Operation
8.2.5
Reset Operation
recommended to connect th
RESET
to ground, which should satisfy the requirement for
most applications. After
RESET
is triggered, the device will be in power down state and
place both the record and the playback pointers at the last message. When a microcontroller
is used for a power-on-Reset,
RESET
must stay active for at least 1
μ
sec after all supply rails
reach their proper specifications. However, this pin must be connected to Vcc if not used.
8.2.6
VOL Operation
Pulsing
VOL
Low changes the volume output. Each pulse on
VOL
will decrease the volume
until the minimum setting is reached. Subsequent pulses will increase the volume until the
ERASE key is Pressed and Held
2.5 seconds (min.)
Case 1 : Current messge location : 1st or Last
Case 2 : Current messge location : Not at 1st or Last
Erase 1st
or last
message
Play
SE2
&/or blink
LED 2x
Wait
Global
Erase
Play
SE4
&/or
blink
LED
4x
Wait
Global
Erase
Play SE1 &/or blink LED 3 times
to Signalify for Global Erase to
start.
Release ERASE key to abort
Global Erase operation
Global Erase Starts
Play
SE1
&/or blink
LED once
Play
SE4
&/or
blink
LED
4x
Play
SE3
&/or blink LED
3x
Play
SE1
&/or blink
LED once
Play
SE1
&/or blink
LED once
Play
SE1
&/or blink
LED once
Play
SE1
&/or blink
LED once
Play
SE1
&/or blink
LED once