User's Manual

HC864-AUTO Hardware User Guide
1vv0300946 Rev.4 – 2012-12-27
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Reserved. Page 47 of 77
The RS232 serial port lines are usually connected to a DB9 connector with the following
layout: signal names and directions are named and defined from the DTE point of view
8.3. 5V UART Level Translation
If the OEM application uses a microcontroller with a serial port (UART) that works at a
voltage different from 2.6, then a circuitry has to adapt the different levels of the two signal
sets. As for the RS232 translation, there are a multitude of single chip translators. For
example a possible translator circuit for a 5V TRANSMITTER/RECEIVER can be: