Kinetis MicrocontrollersのトピックRe: Clarification on I2S transmitters for K22DX256

Clarification on I2S transmitters for K22DX256

scottm — Wed, 26 Jul 2023 03:31:17 GMT

I'm looking for clarification on the I2S/SAI configuration on the K22DX256, namely the number of I2S transmitter channels.

Page 124 of the reference manual says the device includes one I2S:

Page 194 shows two TXD lines:

Which of these is correct?

Thanks,

Scott

Re: Clarification on I2S transmitters for K22DX256

xiangjun_rong — Wed, 26 Jul 2023 08:15:05 GMT

Hi,

As you said that the K22 has ONE SAI module, each SAI module has two transmitter pins I2S0_TXD0/TXD1 and two receiver pins I2S0_RXD0/RXD1.

In I2S mode, each transmitter pin can transfer two channels, so two transmitter pins can transmit 4 channels.

Hope it is helpful

XiangJun Rong

Re: Clarification on I2S transmitters for K22DX256

scottm — Wed, 26 Jul 2023 20:12:54 GMT

That seems to be at odds with what the manual says, though:

If the K22DX256 does indeed have a second transmit line that would be wonderful news because I could use it for a project I thought it wouldn't be suitable for. I just don't see any indication that the second TX line exists aside from the entry in the pinout table. The debugger only shows one "I2S0_TDR", and MK22D6.h only lists I2S0_TDR0.

Thanks,

Scott

Re: Clarification on I2S transmitters for K22DX256

xiangjun_rong — Thu, 27 Jul 2023 02:05:05 GMT

Hi,

I am sorry, the SAI module of K22DX256 just has one transmitter pin I2S0_TXD0 and one receiver pin I2S0_RXD0.

Pls refer to section 3.9.5.1 Instantiation information in K22P48M50SF4RM.pdf, which is RM of MK22DX128VLF5, MK22DX256VLF5.

The SAI transmitter/receiver pins are dependent part number for the same K22 family, some has 1 pin for each transmitter and receiver, some has 2 pins for each transmitter and receiver.

XiangJun Rong

Re: Clarification on I2S transmitters for K22DX256

scottm — Fri, 28 Jul 2023 05:03:51 GMT

So the pinout information is wrong, correct? I couldn't find any newer revisions or documentation errata.

Scott

Re: Clarification on I2S transmitters for K22DX256

xiangjun_rong — Fri, 28 Jul 2023 09:05:46 GMT

Hi,

I suppose that the pin out information is wrong for K22DX256

Only pin 34 can function as I2S0_TXD0, pin 33 can not function as I2S0_TDX1.

Hope it is helpful

XiangJun Rong