SAA7740 Philips Semiconductors, SAA7740 Datasheet - Page 6

• Manufacturer Part Number: SAA7740
• Description: Digital Audio Processing IC DAPIC
• Manufacturer: Philips Semiconductors

Philips Semiconductors
GENERAL DESCRIPTION
The SAA7740H is a function-specific digital signal
processor. The device is capable of performing processing
for listening-environments such as equalization,
hall-effects, reverberation, surround-sound and digital
volume/balance control. The SAA7740H can also be
reconfigured (in a dual and quad filter mode) so that it can
be used as a digital filter with programmable
characteristics.
For reasons of silicon efficiency, the SAA7740H realises
most functions directly in hardware. The flexibility exists in
the possibility to download function parameters, correction
coefficients and various configurations from a host
microcontroller (see Fig.1). The parameters can be
passed in real time and all functions can be switched on
simultaneously.
The communication with a host microcontroller conforms
with the standard I
2 digital stereo signals in the I
sampling frequency (f
outputs.
Mode description
The SAA7740H can be set in four basic modes of
operation.
1997 May 30
Digital Audio Processing IC (DAPIC)
2
C-bus format. The SAA7740H accepts
as
) and provides 2 digital stereo
2
S-bus format at audio
6
G
In the general DAPIC mode two variants are available
(see Figs 3 and 4). In this mode the DAPIC accepts
2 stereo input signals. DC filtering is performed on the
inputs before further processing. On one of the stereo
inputs a 5-band graphic equalization can be performed.
The stereo image of this signal can be controlled from
mono to stereo.
In the first variant (see Fig.3) a stereo hall-effect can be
added to the signal by means of direct reflections. In the
second variant (see Fig.4) a reverberation effect can be
added to the signal by means of exponential decaying
reflections. Surround-sound can then be created for the
rear loudspeakers. The surround-sound module is also
able to provide karaoke.
The surround-sound module accepts the second stereo
input, a microphone signal can be added via the 5-band
equalizer. At the output, each of the 4 channels can be
individually delayed via the external DRAM.
The interfacing and addressing of the DRAM is performed
by the DAPIC.
The applications for the general mode are digital
amplifiers, audio combination sets and TV audio channels.
ENERAL
DAPIC
MODE
Product specification
SAA7740H