I2S pin assignment for Flexcomm6&7 on LPC551x

[sh9]

The Flexcomm6&7 blocks on the LPC551x allegedly support 4 channel pairs each, which requires 4 data pins per Flexcomm. However, I can't find any information of how to configure the pins for this mode of operation. Is this an oversight in the datasheet, or am I missing something?

It seems a similar issue exists for the LPC553x, too. The other LPC55xx family members don't seem to support this special feature on Flexcomm6&7.

See also application note AN12939 Table 1.

[alyeata]

I am currently working on my project which involved LPC551x. This save me lots of time. I will modify the relevant registers to test. Thanks

[sh9 · Accepted solution]

Thank you Alice! I realized that the 4 channel pairs apparently use a single pin, as opposed to 4 separate pins.

This means, however, that the bit clock would have to be 4 times as high. I think the documentation could have been clearer in this respect, but ultimately you're right, it isn't an "issue".

Thanks again!

[Alice_Yang]

Hello @sh9 

There are no  issues regarding the UM and AN.

The LPC55S1x microcontroller's Flexcomm Interfaces 6 and 7 each provide four I2S channel pairs for audio configuration. These interfaces can be programmed by modifying the relevant registers (e.g., P1CFG1 , P2CFG1, P3CFG1 ) in the register map.

 

  

Additionally, the built-in Configuration Tool offers a graphical interface to streamline the setup process.

BR

Alice