They are usually small square chips with 48 pins (48-pin QFP package). Alternatively, sample rate conversion could be performed in the DC97 (controller) or in the software driver.)Ĭodec chips have an AC'97 interface on one side and analog audio interface on the other. Lower sample rates (such as 44.1 kHz) are implemented using a handshake protocol between the controller and codec which skips data during certain frames. However, slots can be combined to provide a 96 kHz sampling rate for the L, R and C channels. Normally, six channels are used for 5.1 surround sound, and three channels are available for modem use. Slots 1, 2 and 12 are used for non-audio data, while slots 3–11 carry up to nine channels of raw pulse-code modulation audio signals. The first (slot 0) is 16 bits long and contains validity flags for the remaining slots, while the remaining 240 bits are divided in twelve 20-bit slots (slots 1–12), used as data slots. This is therefore a time-division multiplexing scheme.Įvery frame is subdivided in 13 slots. The link carries a bidirectional serial data stream at a fixed bitrate (12.288 Mbit/s) between the controller and one or more codecs.Įach 12.288 Mbit/s stream is divided into 256-bit frames (frame frequency is 48 kHz). The first four are outputs from the controller, while sdata_in carries input from the codec. ![]() The AC-Link is a digital link that connects the DC97 (the controller) with the audio "codecs." It is composed of five wires: the 12.288 MHz clock, a 48 kHz sync signal, a reset signal, and two data wires which carry the actual audio data: sdata_out and sdata_in. This revision provides means for the audio codec to supply parametric data about its analog interface much like Intel High Definition Audio. AC'97 2.3 compliant indicates extended configuration information and optional jack sensing supportĪC'97 revision 2.3 enables Plug and Play for the end user.AC'97 2.2 compliant indicates extended audio, enhanced riser audio support, and optional Sony/Philips Digital Interface Format.AC'97 2.1 compliant indicates extended audio feature set (optional variable rate, multichannel, etc.).AC'97 1.x compliant indicates fixed 48 kHz sampling rate operation (non-extended feature set).Further details may exist on the talk page. Please expand the section to include this information. ![]() This section is missing information about revision dates (which year). HD Audio has the capability to define up to 15 output channels, but in practice most motherboards provide no more than 8 channels ( 7.1 surround sound). In 2004, Intel released Intel High Definition Audio (HD Audio) which is a successor that is not backward compatible with AC'97. Intel started shipping the initial I/O Controller Hub support in 1999, and it wasn't until public shaming in 2000, that most PC OEMs started shipping AC'97 audio as the default. The first shipping system was in the Cyrix MediaGX, in 1997. ![]() Integrated audio is implemented with the AC'97 Codec on the motherboard, a communications and networking riser card, or an audio/modem riser card. AC'97 supports a 96 kHz sampling rate at 24-bit stereo resolution and a 48 kHz sampling rate at 24-bit stereo resolution for multichannel recording and playback. an AC'97 audio and/or modem codec, available from several vendors, which contains the analog components of the architecture.ĪC'97 defines a high-quality, 16- or 24- bit audio architecture with 5.1 surround sound support for the PC.an AC'97 digital controller (DC97), which is typically built into the southbridge of the chipset, and.The specification covers two types of components, and the AC-Link digital interface between them: The standard was used in motherboards, modems, and sound cards. JSTOR ( December 2019) ( Learn how and when to remove this template message)ĪC'97 ( Audio Codec '97 also MC'97 for Modem Codec '97) is an audio codec standard developed by Intel Architecture Labs and various codec manufacturers in 1997.Unsourced material may be challenged and removed. Please help improve this article by adding citations to reliable sources. This article needs additional citations for verification.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |