GA3219 Datasheet, PDF (10/14 Pages) Gennum Corporation – Venture-TM Digital DSP System

VENTURE GA3219
Table 3. DYNAMIC EXAMPLE WITH FOUR VALID MEMORIES (T = momentary switch is toggled; 0 = OPEN; 1 = HIGH)
MS2
0
0
0
1
1
1
0
0
0
1
0
0
0
0
0
0
MS
0
T
T
0
T
T
0
T
T
0
0
T
T
T
T
T
Memory A
B
C
D
D
D
C
A
B
D
B
C
A
B
C
A
Static Switch on MS and MS2
This mode uses two static switches to change memories.
Table 4 describes which memory is selected depending on
the state of the switches.
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 is smooth. Otherwise, if one switch is changed
and then the other, the part transitions to an intermediate
memory before reaching the final memory. The part starts in
whatever memory the switches are selecting. If a memory is
invalid, the part defaults to memory A.
This mode is set by programming the ‘MSSMode’
parameter to ‘static’ and ‘Donly’ to ‘disabled’.
Table 4. MEMORY SELECTED IN STATIC SWITCH ON
MS and MS2 MODE; Internal Resistors Set to Pull Down
MS
MS2
Memory
OPEN OPEN
A
HIGH OPEN
B (if valid, otherwise A)
OPEN HIGH
C (if valid, otherwise A)
HIGH
HIGH
D (if valid, otherwise A)
Static Switch on MS, Static Switch on MS2 (Jump to
Last Memory)
This mode uses two static switches to change memories.
Unlike in the previous example, this mode will switch to the
last valid memory when the static switch on MS2 is HIGH.
This means that this mode will only use a maximum of three
memories (even if four valid memories are programmed).
Table 5 describes which memory is selected depending on
the state of the switches.
This mode is set by programming the ‘MSSMode’
parameter to ‘static’ and ‘Donly’ to ‘enabled’.
Table 5. MEMORY SELECTED IN STATIC SWITCH ON
MS, Static Switch on MS2 (Jump to Last Memory)
Mode; Internal Resistors Set to Pull Down
MS
MS2
Memory
OPEN OPEN
A
HIGH OPEN
B (if valid, otherwise A)
OPEN HIGH
D
HIGH
HIGH
D
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 is smooth. Otherwise, if one switch is changed
and then the other, the part transitions 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
if switching MS when MS2 is HIGH.
The part starts in whatever memory the switches are
selecting. If a memory is invalid, the part defaults to memory
A.
Audible Memory Change Indicator
Venture GA3219 can be programmed to produce tones to
indicate a memory change. Using the Interactive Data Sheet,
Venture GA3219 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
to have multiple beeps.
The amplitude and frequency of the memory change tone
can be selected independently from 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 beeps a code to indicate
which memory was selected. The beep sequence is 160 ms
ON, followed by 160 ms OFF, between the beeps. The
memory change beeping code is deciphered in Table 6.
Table 6. MEMORY CHANGE BEEPING CODE
Selected Memory
# Beeps
A
1
B
2
C
3
D
4
Tone Generator
The programmable tone generator is capable of tones of
various amplitudes and frequencies. Upon reception of the
tone enable instruction, Venture GA3219 connects the
output of the tone generator to the input of the D/A converter.
The programmed tone is then output until a tone disable
instruction is issued. When disabled, the normal audio signal
is again connected.
Memory Switch Fader
To minimize potential loud transients when switching
between memories, Venture GA3219 uses a memory switch
fader block. When the memory is changed, the audio signal
is faded out, followed by the memory select indicator beeps
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