CP2108_E104 - RS485 DE signal not constantly asserted

by <a href="http://community.silabs.com/t5/Welcome-and-Announcements/Community-Ranking-System-and-Recognition-Program/m-p/140490#U140490"><font color="#000000"><font size="2">Hero Employee</font></font> </a> jstine on ‎03-31-2017 10:28 AM

Question

Are there any restrictions on using all 4 ports of the CP2108 in RS485 mode?

Answer

There is a bug in revision B02 of the CP2108 that occurs when using the DE signal of RS485 from ports 0 and 1 at the same time, or ports 2 and 3 at the same time.  The bug causes the DE signal to sometimes be deasserted during transmission.  The problem can be avoided by not using channel 0 and 1 in RS485 mode, and not using channel 2 and 3 in RS485 mode.

 

This issue will be fixed in revision B03.