On Tue, Jan 21, 2003 at 7:23 AM, Vinay Mathew wrote: > > I have a few problems with communication between a PC (running > Linux) and a board. Communication is purely serial, through > the UARTs. > > The board is able to send data to the PC, which is properly > received by the PC as well. However, when the PC sends > something to the board, the board is unable to read anything. > There is no problem with the UARTs of the PC. > > I was wondering if it could be an incompatibility issue, as > the UART of the board is of type 16C550, while the UART of the > PC is of type 16550A. > There are (supposed to be) no UART compatibility issues between transmitter and receiver beyond the ability to use _exactly_ the same port configuration at both ends. For example, consider the situation where one end is set for odd parity and the other end is set to even parity. If one end is set to not check parity and the other end ignores data with bad parity, then the link will transfer data successfully in only one direction. The electrical interface used (RS-232/V.24, RS-422, etc.) must also be the same at both ends. If the electrical interface types are not the same, then if the link works at all, it usually works in only one direction. For example, if one end is RS-232/ V.24 (single ended) and the other end is RS-422 (differential), then the RS-422 receiver might get lucky and be able to hear the RS-232 transmitter, but the RS-232 receiver will usually not be able to hear the RS-422 transmitter. Good luck with it, Ed ---------------------------------------------------------------- Ed Vance edv (at) macrolink (dot) com Macrolink, Inc. 1500 N. Kellogg Dr Anaheim, CA 92807 ---------------------------------------------------------------- -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
