MSP3438G Datasheet, PDF (42/84 Pages) Micronas – Multistandard Sound Processor Family

MSP 3438G
PRELIMINARY DATA SHEET
Pins 71, 72 XTAL_IN, XTAL_OUT – Crystal Input and
Output Pins (Fig. 4–14)
These pins are connected to an 18.432 MHz crystal
oscillator which is digitally tuned by integrated capaci-
tances. An external clock can be fed into XTAL_IN
(leave XTAL_OUT vacant in this case). The audio
clock output signal AUD_CL_OUT is derived from the
oscillator. External capacitors at each crystal pin to
ground (AVSS) are required. It should be verified by
layout, that no supply current for the digital circuitry is
flowing through the ground connection point.
Pin 73, TP – This pin enables factory test modes. For
normal operation, it must be left vacant.
Pin 74, AUD_CL_OUT – Audio Clock Output
(Fig. 4–14)
This is the 18.432 MHz main clock output.
Pins 75, 76, NC – Pins not connected.
Pins 77, 78, D_CTR_I/O_1/0 – Digital Control Input/
Output Pins (Fig. 4–13)
These pins serve as general purpose input/output
pins. Pin D_CTR_I/O_1 can be used as an interrupt
request pin to the controller.
Pin 79, ADR_SEL – I²C Bus Address Select
(Fig. 4–12)
By means of this pin, one of three device addresses
for the MSP can be selected. The pin can be con-
nected to ground (I²C device addresses 80/81_hex), to
+5 V supply (84/85_hex), or left open (88/89_hex).
Pin 80, STANDBYQ – Stand-by
In normal operation, this pin must be High. If the MSP
is switched off by first pulling STANDBYQ low and then
(after >1 µs delay) switching off the 5 V, but keeping
the 8-V power supply (‘Stand-by’-mode), the SCART
switches maintain their position and function.
* Application Note:
All ground pins should be connected to one low-resis-
tive ground plane.
All supply pins should be connected separately with
short and low-resistive lines to the power supply.
Decoupling capacitors from DVSUP to DVSS, AVSUP
to AVSS, and AHVSUP to AHVSS are recommended
as closely as possible to these pins. Decoupling of
DVSUP and DVSS is most important. We recommend
using more than one capacitor. By choosing different
values, the frequency range of active decoupling can
be extended. In our application boards we use: 220 pF,
470 pF, 1.5 nF, and 10 µF. The capacitor with the low-
est value should be placed nearest to the pins.
The ASG pins should be connected as closely as pos-
sible to the MSP ground. They are intended for leading
with the SCART signals as shield lines and should not
be connected to ground at the SCART-connector.
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