TI中文支持网pcm1865的i2s协议2单通道已经实现，pcm1865实现4通道是不是就不能用i2s协议了，必须要pcm实现？如果要需要pcm协议来实现，那么在i2s的基础上如何修改。
pcm协议的资料太少，还希望能提点一二。
user151383853：
我想你说得是对的.
i2s 协议并不能支持 4 个通道的数据传输
Fenqiang Guo：
回复 user151383853:
PCM格式的数据格式是怎么样的，在datasheet里找不到有关时序的说明。
Kailyn Chen：
回复 Fenqiang Guo:
关于I2S和PCM：
I2S is a common 4 wire DAI used in HiFi, STB and portable devices. The Tx and Rx lines are used for audio transmission, whilst the bit clock (BCLK) and left/right clock (LRC) synchronise the link. I2S is flexible in that either the controller or CODEC can drive (master) the BCLK and LRC clock lines. Bit clock usually varies depending on the sample rate and the master system clock (SYSCLK). LRCLK is the same as the sample rate. A few devices support separate ADC and DAC LRCLKs, this allows for simultaneous capture and playback at different sample rates.I2S has several different operating modes:-I2S - MSB is transmitted on the falling edge of the first BCLK after LRCtransition.Left Justified - MSB is transmitted on transition of LRC.Right Justified - MSB is transmitted sample size BCLKs before LRCtransition.PCM ===PCM is another 4 wire interface, very similar to I2S, which can support a more flexible protocol. It has bit clock (BCLK) and sync (SYNC) lines that are used to synchronise the link whilst the Tx and Rx lines are used to transmit and receive the audio data. Bit clock usually varies depending on sample rate whilst sync runs at the sample rate. PCM also supports Time Division Multiplexing (TDM) in that several devices can use the bus simultaneously (this is sometimes referred to as network mode).Common PCM operating modes:-Mode A - MSB is transmitted on falling edge of first BCLK after FRAME/SYNC.Mode B - MSB is transmitted on rising edge of FRAME/SYNC.
Fenqiang Guo：
回复 Kailyn Chen:
你的pcm格式下 mode A 与mode B是所有ti产品都有的嘛？
Pcm1865文档里并没有找到关于pcm mode的说明？
有没有关于芯片的时序图或者相关文档说明？
下图是stm32 pcm的时序图,无论如何去配置pcm1865，不管是两通道还是四通道，都没有数据出来。
JS Cao：
你好,我现在也在做PCM1865,可是我单路通道采集还没成功,寄存器0x72的状态总是fade in,请问你采集单通道数据时,有没有什么需要特别设置的寄存器,如果方便可以给我一下寄存器配置的资料吗???真的真的万分感谢,QQ771580291
Fenqiang Guo：
回复 JS Cao:
最近逛论坛，好久了没看到，现在问题解决了吗
