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.

FEATURES
Hardware
• Two digital inputs and two digital outputs in the I2S-bus format (i.e. 4 audio channels)
• Independent input/output interfaces
• Slave input/output interfaces
• Slave processing
• I2C-bus microcontroller interface
• DC filtering at the inputs
• One programmable 2nd-order digital filter unit
• Two multiply accumulate processor units (24 × 16-bit/MAC)
• DRAM interface and address computation unit for external delay lines
• On-chip coefficient and external delay line address storage
• Hardware controlled soft mute via the MUTE pin
• Hardware controlled soft demute via the RST pin
• Operating ambient temperature; −40 to +85 °C.

Software
• 5-band parametric equalizer with selectable centre frequency, slope setting and boost/cut gain settings from −12 to +12 dB
• Stereo width control from mono to stereo to spatial stereo
• Stereo Hall-effects for field acoustics, such as concert halls, with 8 coefficients and 8 delayed taps per channel
• External delay line processing for delays up to 1 second
• Reverberation with selectable reverberation time (up to 5 seconds) and energy
• Three different surround sound programs to obtain a spatial effect on 4 loudspeakers
• Passive DOLBY surround processing with the addition of an external dynamic noise reduction IC
• Karaoke processing
• Dual 16th-order correction filtering
• Quad 8th-order correction filtering
• Digital volume and balance control
• Soft controlled soft mute/demute via the microcontroller interface
• Input switching matrix
• Output rear and front switching matrix.

APPLICATIONS
• Digital amplifiers
• Audio combination sets
• Car audio systems
• TV audio channels.