topic I2C measurement of Rising time and Falling time in Fast mode in 8-bit Microcontrollers https://community.nxp.com/t5/8-bit-Microcontrollers/I2C-measurement-of-Rising-time-and-Falling-time-in-Fast-mode/m-p/799871#M22603 <HTML><HEAD></HEAD><BODY><P>Hi engineer,</P><P></P><P>I have a question, in&nbsp; "NXP Doc. UM10204 I2C-bus specification and user manual Rev. 6 — 4 April 2014"&nbsp; tr and tf are 30%~70%; but in "THE I 2C-BUS SPECIFICATION Ver 2.1 JANUARY 2000" tr and tf seem like 10%~90%.</P><P></P><P>Our device which is Touchpad is working in Fast-mode.</P><P></P><P>Could you tell me why it is changed? Because, when I was a studenet, I read the spec of Rising time and falling time is&nbsp; <SPAN style="color: #ff0000;">10%~90%</SPAN>.</P><P></P><P>Nxp spec</P><P><span class="lia-inline-image-display-wrapper" image-alt="nxp.png"><img src="https://community.nxp.com/t5/image/serverpage/image-id/75939i6F3866452C1FAD3F/image-size/large?v=v2&amp;px=999" role="button" title="nxp.png" alt="nxp.png" /></span></P><P>The I2C-bus spec</P><P><span class="lia-inline-image-display-wrapper" image-alt="I2c.png"><img src="https://community.nxp.com/t5/image/serverpage/image-id/75965i0E36D6ED671632AA/image-size/large?v=v2&amp;px=999" role="button" title="I2c.png" alt="I2c.png" /></span></P><P>thanks.</P></BODY></HTML> Wed, 17 Oct 2018 11:04:35 GMT benny_lee 2018-10-17T11:04:35Z I2C measurement of Rising time and Falling time in Fast mode https://community.nxp.com/t5/8-bit-Microcontrollers/I2C-measurement-of-Rising-time-and-Falling-time-in-Fast-mode/m-p/799871#M22603 <HTML><HEAD></HEAD><BODY><P>Hi engineer,</P><P></P><P>I have a question, in&nbsp; "NXP Doc. UM10204 I2C-bus specification and user manual Rev. 6 — 4 April 2014"&nbsp; tr and tf are 30%~70%; but in "THE I 2C-BUS SPECIFICATION Ver 2.1 JANUARY 2000" tr and tf seem like 10%~90%.</P><P></P><P>Our device which is Touchpad is working in Fast-mode.</P><P></P><P>Could you tell me why it is changed? Because, when I was a studenet, I read the spec of Rising time and falling time is&nbsp; <SPAN style="color: #ff0000;">10%~90%</SPAN>.</P><P></P><P>Nxp spec</P><P><span class="lia-inline-image-display-wrapper" image-alt="nxp.png"><img src="https://community.nxp.com/t5/image/serverpage/image-id/75939i6F3866452C1FAD3F/image-size/large?v=v2&amp;px=999" role="button" title="nxp.png" alt="nxp.png" /></span></P><P>The I2C-bus spec</P><P><span class="lia-inline-image-display-wrapper" image-alt="I2c.png"><img src="https://community.nxp.com/t5/image/serverpage/image-id/75965i0E36D6ED671632AA/image-size/large?v=v2&amp;px=999" role="button" title="I2c.png" alt="I2c.png" /></span></P><P>thanks.</P></BODY></HTML> Wed, 17 Oct 2018 11:04:35 GMT https://community.nxp.com/t5/8-bit-Microcontrollers/I2C-measurement-of-Rising-time-and-Falling-time-in-Fast-mode/m-p/799871#M22603 benny_lee 2018-10-17T11:04:35Z