In message <200109301003.06903@EO>, Bart Kus writes:
> Hello, I'm wondering about a seemingly simple sio.c modification. The >problem stems from me wanting to use this dang remote control receiver, which >manipulates the CD line of the serial port it plugs into. Afaik, the UART >itself is capable of generating an interrupt whenever CD changes. The >problem is, sio.c doesn't support this feature. I'm stuck with polling the >status register to find out the state of CD. Not a very good solution for a >daemon that's supposed to run in the background all the time, especially >since the CD line will be toggled at about 40kHz (I think that's the remote >control frequency standard). Perhaps I'm wrong about the 40kHz figure. Your machine will not work too well if it is 40kHz. The PPS-API allows you to timestamp edges on DCD, if the frequency is more reasonable, that would work for you. Find RFC27xx for more info about PPS-API. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-hackers" in the body of the message
