Rainbow Electronics ISD1600B - Manual (Page 10)

ISD1600B SERIES
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at the end of the message. During a record cycle, the device powers down immediately after
REC is released to High.
6.2. F UNCTIONAL D ESCRIPTION E XAMPLE
The following example operating sequences demonstrate the functionality of the ISD1600B series.
6.2.1. Record a Message
The device starts recording from the beginning of the memory when REC transits from High
to Low and stays at Low. A record cycle is completed when REC is pulled to High or entire
memory is filled up. Then an End-of-Message (EOM) marker is written at the end of message,
enabling a subsequent playback cycle to terminate appropriately. Hence, the device
automatically enters into standby mode.
Record takes precedence over playback operation. If REC is pulled Low during a playback
cycle, the playback immediately halts and recording starts from the beginning of the memory.
Holding REC Low after recording will increase standby current consumption.
6.2.2. Edge-trigger Playback
A playback operation starts from the beginning of the memory when PLAYE detects a low
going signal exceeding the specified debounced time. Playback continues until an EOM
marker is encountered. Upon completion of a playback cycle, the device automatically enters
into standby mode.
During playback, a subsequent low going signal will terminate the current playback operation.
Holding this pin Low after playback operation will increase standby current consumption.
6.2.3. Level- trigger Playback
When PLAYL switches from High to Low and stays at Low, a playback starts from the
beginning of the memory until either an EOM marker is reached, then it automatically powers
down.
If PLAYL is pulled High at any time during playback, the playback operation stops
immediately and the device enters into the power-down mode.
6.2.4. LED Operation
The LED is Low during recording, which turns on an LED as a recording indicator. However,
during playback, the LED blinks a few times per second to indicate a playback operation. It
returns to a High when operation stops.
6.2.5. R
OSC
Operation
The duration can be varied by changing the value of R
OSC
. This means the designer has the
flexibility to choose different sampling frequency, up to 12 KHz, depending upon the needs.
This feature allows frequency shifting where a recorded audio can be played back faster or
slower than normal for special sound effects.
Another feature is a “Pause” function that can be activated by taking the R
OSC
resistor to V
CC
to
stop playback momentarily, and to resume when the resistor is switched back to ground.