| .. | .. |
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| 17 | 17 | frame is 21uS long and is divided into 13 time slots. |
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| 18 | 18 | |
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| 19 | 19 | The AC97 specification can be found at : |
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| 20 | | -http://www.intel.com/p/en_US/business/design |
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| 20 | +https://www.intel.com/p/en_US/business/design |
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| 21 | 21 | |
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| 22 | 22 | |
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| 23 | 23 | I2S |
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| 24 | 24 | === |
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| 25 | 25 | |
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| 26 | 26 | I2S is a common 4 wire DAI used in HiFi, STB and portable devices. The Tx and |
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| 27 | | -Rx lines are used for audio transmission, whilst the bit clock (BCLK) and |
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| 27 | +Rx lines are used for audio transmission, while the bit clock (BCLK) and |
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| 28 | 28 | left/right clock (LRC) synchronise the link. I2S is flexible in that either the |
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| 29 | 29 | controller or CODEC can drive (master) the BCLK and LRC clock lines. Bit clock |
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| 30 | 30 | usually varies depending on the sample rate and the master system clock |
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| .. | .. |
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| 49 | 49 | |
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| 50 | 50 | PCM is another 4 wire interface, very similar to I2S, which can support a more |
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| 51 | 51 | flexible protocol. It has bit clock (BCLK) and sync (SYNC) lines that are used |
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| 52 | | -to synchronise the link whilst the Tx and Rx lines are used to transmit and |
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| 52 | +to synchronise the link while the Tx and Rx lines are used to transmit and |
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| 53 | 53 | receive the audio data. Bit clock usually varies depending on sample rate |
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| 54 | | -whilst sync runs at the sample rate. PCM also supports Time Division |
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| 54 | +while sync runs at the sample rate. PCM also supports Time Division |
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| 55 | 55 | Multiplexing (TDM) in that several devices can use the bus simultaneously (this |
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| 56 | 56 | is sometimes referred to as network mode). |
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| 57 | 57 | |
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