OVERVIEW
YMF744B (DS-1S) is a high performance audio controller for the PCI Bus. DS-1S consists of two separated
functional blocks. One is the PCI Audio block and the other is the Legacy Audio block. PCI Audio block
allows Software Driver to handle maximum of 73 concurrent audio streams with the Bus Master DMA engine.
The PCI Audio Engine converts the sampling rate of each audio stream and the streams are mixed without
utilizing the CPU or causing system latency. By using the Software Driver from YAMAHA, PCI Audio
provides 64-voice XG wavetable synthesizer with Reverb and variation. It also supports DirectSound hardware
accelerator, Downloadable Sound (DLS) and DirectMusic accelerator.
Legacy Audio block supports FM Synthesizer, Sound Blaster Pro, MPU401 UART mode and Joystick
function in order to provide hardware compatibility for numerous PC games on real DOS without any software
driver. To achieve legacy DMAC compatibility on the PCI, DS-1S supports both PC/PCI and Distributed
DMA protocols. DS-1S also supports Serialized IRQ for legacy IRQ compatibility.
DS-1S supports the connection to AC'97 which provides high quality DAC, ADC and analog mixing, and it
can connect two AC'97s. In addition, it supports consumer IEC958, Audio Digital Interface (SPDIF), to
connect external audio equipment by digital.
FEATURES
• PCI 2.2 Compliant
• PC'98/PC'99 specification Compliant
• PCI Bus Power Management rev. 1.0 Compliant
(Support D0, D2 and D3 state)
• Supports clock run
• PCI Bus Master for PCI Audio
True Full Duplex Playback and Capture with
different Sampling Rate
Maximum 64-voice XG capital Wavetable
Synthesizer including GM compatibility
DirectSound Hardware Acceleration
DirectMusic Hardware Acceleration
Downloadable Sound (DLS) level-1
• Legacy Audio compatibility
FM Synthesizer
Hardware Sound Blaster Pro compatibility
MPU401 UART mode MIDI interface
Joystick
• Supports Serialized IRQ
The contents of this catalog are target specifications and are subject to change
without prior notice. When using this device, please recheck the specifications.
YMF744B
DS-1S
YAMAHA CORPORATION
• Supports PC/PCI and Distributed DMA for legacy
DMAC (8237) emulation
2
• Supports I
S serial input for Zoomed Video Port
• Supports Consumer IEC958 Output (SPDIF OUT)
• Supports Consumer IEC958 Input (SPDIF IN)
• Supports AC'97 Interface (AC-Link) Revision 2.1
• AC'97 Digital Docking
• Supports 4-Channel Speaker
• Hardware Volume Control
• EEPROM Interface
• Single Crystal operation (24.576MHz)
• 3.3V Power supply (5V tolerant)
• 128-pin LQFP
YMF744B-V : 0.5mm pin pitch
YMF744B-R : 0.4mm pin pitch
CATALOG No.:LSI-4MF744B00
Preliminary
YMF744B CATALOG
December 18, 1998
February 3, 1999