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Can we access I2C in 7-bit data ?

ranran
Senior II

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

1 ACCEPTED SOLUTION

Accepted Solutions
S.Ma
Principal

I2C specification states 8 bit data + ACK bit.

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

View solution in original post

6 REPLIES 6
S.Ma
Principal

I2C specification states 8 bit data + ACK bit.

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

S.Ma
Principal

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

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.

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ranran
Senior II

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

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

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

Thanks