Advanced Digital Audio Multi channel decode processor
The YSS944 (ADAMB-f)/YSS943 (ADAMB-b)/YSS940 (ADAMB-nd) is an audio decoding digital signal
processor that integrates onto a single chip the various digital signal processing functions required for AV
amplifiers, etc. It includes an advanced 32-bit floating-point DSP and is able to decode a variety of audio
• The contents described in this manual are implemented by downloading boot firmware.
For detailed information about the boot firmware, please contact YAMAHA.
• The YSS943 cannot execute DTS-ES and DTS Neo:6 decoding.
• The YSS940 cannot execute any decoding related to DTS (DTS, DTS-ES, DTS 96/24, and DTS Neo:6).
• Supports various types of decoding up to 7.1 channels (5.1/6.1/7.1 channels selectable).
• 5.1-channel decoding of Dolby Digital (AC-3), DTS, AAC.
• 6.1-channel decoding of Dolby Digital EX, DTS-ES.
• DTS 96/24 decoding and audio interface clock division/switching functions.
• Dolby Pro Logic IIx and DTS Neo:6 decoding
• Tone control and bass management functions
• Function modification/expansion by downloading firmware to on-chip memory
• Lip-sync function that enables synchronization of voice and video with variable voice delay
• Supports sampling frequencies up to 192 kHz during PCM playback.
• 1/2 down sampling function when two PCM channels are played back
• Dolby Digital/DTS/AAC decode information output function (can be read by microprocessor)
• High-speed/high-accuracy operation by 32-bit floating-point DSP
Operating frequency: 180 MHz (178.176 MHz)
Data bus width: 32 bits (24-bit mantissa and 8-bit exponent)
Multiplier/adder: 32 bits × 32 bits + 55 bits → 55 bits (47-bit mantissa and 8-bit exponent)
• No external memory needed (external memory is used when delay is increased.)
• Eight general I/O ports
• On-chip PLL for generation of high-speed internal operating clock
• Supply voltage: 1.2 V (core block) and 3.3 V (pin block)
• Low power consumption: about 210 mW (standard value during Dolby Digital decoding)
• Si-gate CMOS process
• Lead-free plating LQFP144 package (YSS944-VZ, YSS943-VZ, and YSS940-VZ)
“Dolby,” ”Dolby Pro Logic IIx,” and “AC-3” are trademarks of Dolby Laboratories.
“DTS,” “DTS-ES,” “DTS 96/24,” and “DTS Neo:6” are trademarks of Digital Theater Systems, Inc.
• AV amplifiers for home theaters
• Car audio systems
CATALOG No.: LSI-4SS944A31