How LPC5514JBD64 connect Audio Codec

[shaozhongliangs]

Customer: Shenzhen DJI

PN:LPC5514JBD64 

Project:handle charging accessory

Question:

   DJI is evaluating LPC5514JBD64 in handle charging accessory. It need 4 channel MICs input. Customer wanted to how  the LPC5514JBD64 connect with Audio Codec. Customer asked if we could provide a reference schematics.

   Customer confused about the Flexcomm description: Only Flexcomm0~5 could service as I2S Master? If yes, Flexcomm0~5 each just provide one channel I2S, how to connect 4 MICs?

[xiangjun_rong]

Hi, ZhongLiang,

As the following screenshot, all the FC modules including the FC0 to FC7 support I2S mode, each FC module can function as either I2S transmitter or Receiver but not both. In other words, you can connect each Mic to any one of FCx.

As you know that the I2S module only has two slots(left slot and right slot), any FC module from FC0 to FC7 supports I2S mode. But there is TDM mode(Time Division Module), which consists of multiple slots, the FC0~FC5 supports 2 slots, the FC6 and FC7 support at most 8 slots.

In conclusion, you can use any 4 FC modules out of 8 FC modules to connect to 4 Mics.

Hope it can help you

BR

XiangJun Rong

[shaozhongliangs]

@xiangjun_rong @Thank you for your reply. DJ evaluating some quad audio Codecs which have block diagrams like the attached screenshot. Apart from TDM mode as you mentioned, customer would use the two data lines(DO12,DO34) to transfer 4-channel audio data.

  Customer is wondering if it is OK to use the following PIOs in Flexcomm6 to connect the four signals mentioned above?

[xiangjun_rong]

Hi,

Regarding your question, I have to say that you have to use two FC modules instead of one, because you have two data pins.

One solution is that you use independent SCK/WS/Data pins for each FC module, for example

FC5_SCK/FC5_WS/FC5_DATA to one Mic, FC6_SCK/FC6_WS/FC6_DATA to another Mic.

Another solution:

FC5_SCK/FC5_WS/FC5_DATA to one Mic. Connect FC5_SCK/FC5_WS to another Mic,FC6_DATA to another mic.

There is Chapter 36: LPC55S1x/LPC551x Sys_ctrl in UM11295.pdf, one FC module clock and frame clock can be shared with another one.

Hope it can help you

BR

XiangJun Rong

[shaozhongliangs]

@xiangjun_rong Thank you!  DJI will try the solution 2 “FC5_SCK/FC5_WS/FC5_DATA to one Mic. Connect FC5_SCK/FC5_WS to another Mic, FC6_DATA to another mic.” , because it may be a better choice to user application.

    Here is a new question:

       If the other data line is connected to FC6_DATA, can the FC6_SCK /FC6_WS  pins work as normal GPIOs?

[xiangjun_rong · Accepted solution]

Hi,

Yes, If the other data line is connected to FC6_DATA, the FC6_SCK /FC6_WS  pins can work as normal GPIOs.

BR

XiangJun Rong