libftdi Archives

Subject: Re: ftdi_read loses bytes (when latency is low)

From: Anders Larsen <al@xxxxxxxxxxx>
To: libftdi@xxxxxxxxxxxxxxxxxxxxxxx
Date: Sun, 07 Dec 2014 15:00:29 +0100
On 2014-12-07 10:51, Rogier Wolff wrote:
Whoa! As far as I can see we're talking about the latency timer in the
FTDI chip.

yes indeed

http://www.ftdichip.com/Support/Documents/AppNotes/AN232B-04_DataLatencyFlow.pdf

The PC will assume "more data available" when the packet is 64 bytes!

So... For setting the latency timer: NEVER EVER set it below the time
required to gather 64 bytes. (unless your data transfer is slow
compared to 64 bytes/ms.).

interesting info - thanks for the (important) hint!

Cheers
Anders
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