LPC MicrocontrollersのトピックRe: I2S pin assignment for Flexcomm6&7 on LPC551x

I2S pin assignment for Flexcomm6&7 on LPC551x

sh9 — Tue, 11 Mar 2025 18:51:47 GMT

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.

Re: I2S pin assignment for Flexcomm6&7 on LPC551x

Alice_Yang — Wed, 12 Mar 2025 07:00:55 GMT

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.

Alice

Re: I2S pin assignment for Flexcomm6&7 on LPC551x

sh9 — Thu, 13 Mar 2025 08:22:24 GMT

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!

Re: I2S pin assignment for Flexcomm6&7 on LPC551x

alyeata — Mon, 14 Apr 2025 07:37:21 GMT

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