Messages in this thread | | | Date | Wed, 27 Oct 1999 11:00:41 -0400 | From | "Theodore Y. Ts'o" <> | Subject | Re: Half duplex serial support |
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Date: Wed, 27 Oct 1999 14:19:52 +0100 From: David Woodhouse <David.Woodhouse@mvhi.com>
Mostly, we have FIFOs in hardware and we don't actually receive each byte. IIRC, the behaviour of a 16550a is to interrupt either when the FIFO gets to a certain fullness, or if there's data in the FIFO and then an idle period.
If the latter is configurable, then we can set it to 33 bit times, and then any interrupt without a full FIFO tells us that there was an idle period.
It's not configurable, and unfortunately the idle timeout is 4 character times.... which is too long. So if you really care about getting the exact 3 character timeout, you'd have to diable the receive FIFO on the UART. Ugly! Or you can cheat and just check for 44 bit times. :-)
- Ted
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