Minimum SCL data rate of I2C Slave for PSoC4000S

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YoIs_1298666
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Hello,

There is a data rate range recommended by the I2C master,

YoIs_1298666_0-1633927393619.png

Can the I2C master select a data rate in the range of 0-100 kbps when the I2C slave setting is in Standard-mode and 0-400 kbps when it is in Fast-mode?

Best regards,

Yocchi

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ncbs
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Hello Yocchi-san,

I agree with you regarding the IMO deviation👍

If the I2C master is 99kbps, is it correct to understand that the I2C slave of PSoC 4 should be set to 400kbps (max 392kbps deviation of ± 2%)?

I2C will work even if the slave is set at higher data rate, as the clock supplied by the master finally controls the I2C data rate.

I do not understand the reason behind choosing PSoC4 at the 400kbps range: It is recommended to set the slave to the same data rate settings.

 

Best regards,
Nikhil 😊

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ncbs
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Hi @YoIs_1298666,

In I2C communication, the clock signal is supplied by the master to all the slaves on the SCL line. Hence the communication will take place at the rate decided by the clock signal on the SCL line. 


There would be no problem if the slave is set to a higher rate than the master because the clock is set by the master. But, on the other hand, master cannot be faster than the slave as slave will not be able to receive and process all the data.

 

Generally, it is recommended to use the same modes and rates both for the master and the slave.

 

Best regards,
Nikhil  

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Hello Nikhil-san,

Thank you very much for your support.

I fully understand what you mean.

The IMO of PSoC4 has a deviation of ± 2%, so setting the I2C slave to 100kbps only guarantees up to 98kbps. 

https://community.cypress.com/t5/PSoC-4-MCU/Maximum-SCL-data-rate-of-I2C-Slave-for-PSoC4000S/m-p/288...

 

If the I2C master is 99kbps, is it correct to understand that the I2C slave of PSoC 4 should be set to 400kbps (max 392kbps deviation of ± 2%)?

Best regards,

Yocchi

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ncbs
Moderator
Moderator
Moderator
500 replies posted 50 likes received 250 sign-ins

Hello Yocchi-san,

I agree with you regarding the IMO deviation👍

If the I2C master is 99kbps, is it correct to understand that the I2C slave of PSoC 4 should be set to 400kbps (max 392kbps deviation of ± 2%)?

I2C will work even if the slave is set at higher data rate, as the clock supplied by the master finally controls the I2C data rate.

I do not understand the reason behind choosing PSoC4 at the 400kbps range: It is recommended to set the slave to the same data rate settings.

 

Best regards,
Nikhil 😊

0 Likes