On Thursday 01 April 2010 01:36:52 pm Fabio Giovagnini wrote: > I' have connected my SCIF1 port (of sh2a 7203) to a MAX485, and the > TXEn/!RxEn to an I/O port. > I had the idea to write a driver for proc FS to manage the TxEn/!RxEn line > and using the ttySCx driver to send and receive data at 38400. > But I need to wait the end of the last byte trasmission before to set low > the TxEn/!RxEn line. > Now I'm doing it with a dilay time; but I was looking for a more elegent > solution
There are a couple of solutions that are more elegant. First is to have a "transmitter shift register empty" interrupt deassert the line, but that's not the most elegant, if you hardware has support to automatically control the RS485 transmitter enable pin. Some UARTs have the ability to do this (ColdFire does for sure, I've never used SH2A) but check your UART documentation for the ability to automatically control a transmit enable pin. -A. _______________________________________________ uClinux-dev mailing list uClinux-dev@uclinux.org http://mailman.uclinux.org/mailman/listinfo/uclinux-dev This message was resent by uclinux-dev@uclinux.org To unsubscribe see: http://mailman.uclinux.org/mailman/options/uclinux-dev
