Can we access I2C in 7-bit data ?

[ranran]

Hello,

As far as I understand, I2C access with STM32H7 supports only 8-bit data.

But we need 7-bit data. Is that possible ?

Thanks

[S.Ma · Accepted solution]

I2C specification states 8 bit data + ACK bit.

If 7 bits then it's no longer called I2C.

[S.Ma]

And then the answer is no. Use SW I2C with GPIO to build customized waveforms for the pseudo I2C.

Or maybe there is confusion for the slave address, it's 7 bit + Read/write bit = 8 bits

[Tesla DeLorean]

Perhaps you can post information about what device you're trying to communicate with, and the "7-bit" mode you're talking about.

The address is 7-bit wide, perhaps you're confusing terms/requirements, but question lacks sufficient context.

[ranran]

Hi,

I was speaking of data width - not address mode.

So, according to previous answers here, it seems that data must be used with 8-bit bytes only.

Thank you

[Tesla DeLorean]

Ok, but it what context? What device needs/provides such a mode?

[ranran]

It is not for a specific device, but only optional for any for future device requiring 7-bits data.

Thanks