GA3216 Datasheet, PDF (12/14 Pages) Gennum Corporation – FOUNDATION-TM Digital Single or Dual Channel DSP Compression System

MS
OPEN
HIGH
OPEN
HIGH
MS2
OPEN
OPEN
HIGH
HIGH
Memory
A
B (if valid otherwise A)
Last Valid Memory
Last Valid Memory
In this mode it is possible to jump from any memory to any
other memory simply by changing the state of both
switches. If both switches are changed simultaneously then
the transition will be smooth, otherwise, if one switch is
changed and then the other, the part will transition to an
intermediate memory before reaching the final memory.
When MS2 is set HIGH, the state of the switch on MS is
ignored. This prevents memory select beeps from occurring
when switching MS when MS2 is HIGH.
The part will start in whatever memory the switches are
selecting. If the device starts up in a memory other than A,
and the memory beep tones are enabled, the device will
emit the corresponding tones for that memory. If a memory
is invalid, the part will default to memory A.
AUDIBLE MEMORY CHANGE INDICATOR
The FOUNDATION Digital can be configured to produce
tones to indicate a memory change.
Through ARKonline the GA3216 can be configured to either
enable or disable the Memory Change Indicator. When the
Memory Change Indicator is enabled, there is an option to
have a single beep for each memory change or multiple-
beeps.
The amplitude and frequency of the memory change tone
can be selected independent of the Tone Generator
settings and can be individually selected for each memory.
When the memory change multiple beep is enabled and the
memory change tone is enabled, then during a memory
change operation the selected tone will beep a code to
indicate which memory has been selected. The beep
sequence will be 150ms ON followed by a 150ms OFF time
between the beeps. The memory change beeping code is
deciphered in the table below.
SELECTED MEMORY
A
B
C
D
# OF BEEPS
1
2
3
4
TONE GENERATOR
The tone generator is capable of producing programmable
tones. When the Tone Generator is enabled, the
FOUNDATION Digital connects the output of the tone
generator to the input of the D/A converter. The
programmed tone is the output until the Tone Generator is
disabled. When disabled, the normal audio signal path is
again connected. The tone generator will produce a beep
to indicate a memory select change, a microphone/telecoil
selection change or to warn the user of low battery voltage.
NOTE: When the sampling frequency is set at 24kHz, the
tones will scale. e.g. A 1kHz tone at 32kHz sampling would
be approximately 667Hz at 24kHz sampling.
LOW BATTERY INDICATOR (POWER-ON/POWER-OFF)
During power-on the FOUNDATION Digital is held in a reset
state until V_b reaches a turn-on threshold, and the hybrid's
internal control logic determines that the supply is stable.
When this occurs the hybrid begins its power-on sequence.
When a low battery condition (below turn on threshold) is
detected, the FOUNDATION Digital sends out a series of 3
beeps (225ms ON, 225ms OFF, 225ms ON, 225ms OFF,
225ms ON) to indicate the battery is low. This will repeat
every 5 minutes until the device reaches the turn-off
threshold.
If Vb drops below the turn-off threshold then the
FOUNDATION Digital is returned to its reset state and the
audio output is muted.
There are four reset modes which are selectable through
ARKonline.
The first is the shallow-reset mode which, during the power-
ON sequence circuit starts when the supply voltage rises
above the turn-ON threshold after shutdown. The device will
function until the supply voltage drops below the turn-OFF
threshold but will recover when the device rises above the
turn-ON threshold again.
The second is deep-reset mode which begins when the
supply voltage rises above the turn-ON threshold after
shutdown. Once the supply voltage drops below the turn-
OFF threshold the GA3216 will shut down and remain there
until the supply voltage drops below approximately 0.3V
and subsequently rises above the turn-ON threshold after
shutdown.
The third is a combination of these two modes, where the
device starts up in shallow-reset mode initially, then
changes over to deep reset mode after 5 minutes.
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