YMF744B

58-59h: ACPI Mode

Read / Write

Default: 0000h

Access Bus Width: 8, 16, 32-bit

 

b15

b14

b13

b12

b11

b10

b9

b8

b7

b6

b5

b4

b3

 

b2

 

b1

 

b0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

-

-

-

-

-

-

-

-

-

-

-

-

-

 

-

 

-

 

ACPI

b0................ACPI: ACPI Mode Select

 

 

 

 

 

 

 

 

 

 

 

 

 

 

This bit select either PCI Bus Power Management or ACPI Mode for power management of DS-1S.

 

 

 

 

“0”: PCI Bus Power Management is used. CAP bit (06-07h: Status Register) and Capabilities Pointer

 

 

 

(34h) are enabled.

(default)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

“1”: ACPI Mode is used.

CAP bit and Capabilities Pointer are hardwired “0”, and disabled.

 

 

 

 

 

5A-5Bh: DS-1S Secondary AC’97 Power Control

Read / Write

Default: 0000h

Access Bus Width: 8, 16, 32-bit

b15

b14

b13

b12

b11

b10

b9

b8

b7

b6

b5

b4

b3

b2

b1

b0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

-

-

-

-

-

-

-

-

SPR7

SPR6

SPR5

SPR4

SPR3

SPR2

SPR1

SPR0

b0................SPR0: Secondary AC’97 Power Down Control 0

This bit controls the power state of the ADC and Input Mux in the Secondary AC’97.

 

“0”: Normal

(default)

 

“1”: Power down

 

b1

................SPR1: Secondary AC’97 Power Down Control 1

This bit controls the power state of the DAC in the Secondary AC’97.

“0”: Normal(default)

“1”: Power down

b2................SPR2: Secondary AC’97 Power Down Control 2

This bit controls the power state of the Analog Mixer (Vref still on) in the Secondary AC’97. This power state retains the Reference Voltage of the AC’97.

“0”: Normal(default)

“1”: Power down

b3................SPR3: Secondary AC’97 Power Down Control 3

This bit controls the power state of the Analog Mixer (Vref off) in the Secondary AC’97. This power state removes Reference Voltage of the AC’97.

“0”:

Normal

(default)

“1”:

Power down

 

February 3, 1999

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Page 29
Image 29
Yamaha YMF744B (DS-1S) specifications 58-59h Acpi Mode, 5A-5Bh DS-1S Secondary AC’97 Power Control

YMF744B (DS-1S) specifications

The Yamaha YMF744B, also known as the DS-1S, is a popular audio chip that emerged in the late 1990s, particularly known for its use in sound cards for PCs. This sound processor exemplifies Yamaha's commitment to delivering high-quality audio through innovative technology and user-friendly features.

One of the standout features of the YMF744B is its ability to support advanced sound synthesis methods, including wave table synthesis and sample playback. These technologies provide users with a rich audio experience, enabling high-fidelity sounds reminiscent of live instruments. The chip is also notable for its ability to emulate MIDI instruments, allowing musicians to create synthesized music that captures the nuances of traditional sounds.

The YMF744B integrates a 16-bit DAC (Digital-to-Analog Converter), which facilitates high-quality audio playback with a sampling rate of up to 48 kHz. This capability ensures that sound reproduction remains clear and devoid of distortion, appealing to both casual users and audio professionals alike. Additionally, the chip supports multiple audio channels, making it ideal for gaming and multimedia applications where spatial audio is crucial.

Another significant feature of the YMF744B is its support for various audio formats, including PCM (Pulse Code Modulation), ADPCM (Adaptive Differential Pulse Code Modulation), and even MIDI. The versatility in format support allows users to interact with a broad spectrum of audio applications, from game design to music production.

The chip also comes with integrated Sound Blaster Pro compatibility, which significantly enhances its usability with a vast array of software and games designed during the 1990s and early 2000s. This compatibility is crucial for retro gaming enthusiasts who seek an authentic audio experience with classics from the past.

Moreover, the YMF744B champions power efficiency, making it an attractive choice for mobile computing platforms. Its low power consumption means that it can be effectively used in laptops without significantly draining battery life, allowing users to enjoy high-quality sound on the go.

In summary, the Yamaha YMF744B (DS-1S) stands out due to its advanced audio synthesis capabilities, high-quality playback features, and compatibility with multiple formats. These attributes make it a favored choice in the audio processing domain, continuing to impact computer audio technology long after its initial release.