isd1740a Winbond Electronics Corp America, isd1740a Datasheet - Page 16

• Manufacturer Part Number: isd1740a
• Description: Multi-message Single-chip Voice Record&playback Devices
• Manufacturer: Winbond Electronics Corp America

b) Global Erase: Level-triggering this pin at Low for more than 2.5 seconds initiates the
Triggering
operation and will be ignored. However, triggering
during playback will delete the current played message, if it is the first or last one.
Figure 7.1: Global Erase Operation
7.1.5
A 0.1 PF capacitor is recommended to connect
used on this pin. When
playback pointers at the last message. When a microcontroller is used for a power-on-Reset,
x If the device is idle and the playback pointer is not currently pointing to the first or last
x If the device is currently playing the first or last message, pressing
Global Erase operation and deletes all messages, except the SEs. If SEs are present, the
device will play SE1 three times after
released during the playback of SE1, all messages will be erased, and the chip will play
SE4. See Figure 7.1 for the operation details. The
Case 1 :
Case 2 :
message:
o
o
o
the current message, as in the related cases described above.
Reset Operation
ERASE key is Pressed and Held
No message is erased.
SE3, if present, will be played and the LED will flash twice.
Play pointer will be unchanged.
ERASE
Erase 1st
message
Current messge location : Not at 1st or Last
Current messge location : 1st or Last
or last
Play
SE3
for individual erase during a record or forward operation is an illegal
Play
SE2
RESET
2.5 seconds
Wait
is triggered, the device will place both the record and the
Wait
- 16 -
ERASE
Release ERASE key to abort the
Play SE1 3 times to Warn for
RESET
Play
SE1
Play
SE1
is held for 2.5 seconds. If
Glabal Erase to start.
ERASE
ERASE
operation
to ground if a push button switch is
Play
SE1
Play
SE1
ISD1700A SERIES
for an individual erase operation
is debounced internally.
Global Erase Starts here
Play
SE1
Play
SE1
Global
Global
Erase
Erase
ERASE
Play
SE4
Play
SE4
ERASE
will delete
is not