Serial port commonly to as RS232 communication is the most widely used interface in embedded systems. Whether it be micro-controller, processor, FPGA the basic interface and the slowest interface that is used is serial port. RS232 communication complies to requirements of EIA/TIA-232 and V.24/V.28 standards. the two main terminologies we come across in these standards are DTE and DCE.
DTE is nothing but an equipment which transmits or receives digital data. This equipment processes the data and converts it into relevant form the users. One of the best examples of DTE is Personal computer (PC). The other examples include printers, fax machines, etc.
DCE is nothing but a simple level converter kind of circuit to make the DTE compatible with communication equipment. Sometimes DCE is a part of DTE and doesn't exist independently. Modems existing in the market are an example of DCE.
The following figure shows the connectivity between DTE and DCE in it's simplest form.
Note: RS232 full form --> Recommended standard-232
