Instruction Manual

ISD1916
Publication Release Date: September 11, 2007
- 15 - Revision 0
Fig. 9: Playback Operation under FMC mode
Sp+
Sp-
LED
FM3
Norm/Mode
FM2
FM1
M1 ~ M4
Stop Start
End of Message
R / P
Start
T
FSet
T
Deb
T
Deb
T
Deb
T
EOM
T
Settle2
6.3. OTHER OPERATIONS
6.3.1. Rosc Operation
• When the R
OSC
varies from 53.3 KΩ to 160 KΩ, the sampling frequency changes from 12 to 4 kHz
accordingly.
• When R
OSC
resistor value is changed during playback, the tone of a recorded message will alter either
faster or slower.
• If the ground side of R
OSC
resistor is floated or tied to V
CC
, then the current operation will be freezed.
• The operation will resume when the resistor is connected back to ground.
6.3.2. LED Operation
• LED turns on during recording. Also, LED pulses Low at the end of message. The Low period must
be sufficiently greater than debounce time.
6.3.3. Feed-Through mode Operation
• As FT is held Low, the Mic+ pin will be reconfigured as AnaIn input then the AnaIn signal will be
transmitted to the speaker outputs. Under this mode, Mic- pin is not used (must be floated).
• After
FT is enabled, If REC is triggered, then AnaIn signal will be recorded into memory while the
Feed-Through path remains on.
• If
FT is already enabled, activating either PlayE or PlayL will first disable the FT path then play the
recorded message. Once playback completes, FT path will be resumed.
• During an operation, activating the
FT
pin is not allowed.
6.3.4. Power-On Playback Operation
• If PlayE is kept at Low during power turns on, the device plays message once, then powers down.