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RE: slow parallel port


The parallel port driver connects to the parallel port framework
and uses its bitbangning scheme to drive the parallel port. This
is a simple but inefficient way to do it. I have a skeleton
for a real DMA based ECP driver that I know several customers
have been able to modify to a working driver. It should be easy
to modify this into an EPP driver. 

It would be best if someone on this list could send you a working
ECP driver. Otherwise I can send you the skeleton driver.

-----Original Message-----
From: owner-dev-etrax@xxxxxxx.com">mailto:owner-dev-etrax@xxxxxxx.com] On
Behalf Of Peter van Duijn
Sent: Thursday, October 23, 2003 8:45 AM
To: dev-etrax
Subject: slow parallel port


I'm currently working on a project that requires high speed data
from and to the parallel port 0.
As a first try I want to use the standard parport driver and device
/dev/parpor0 (in EPP mode)
I've got data going out but the speed is about 115 KBytes/sec (measured
between the first data bit and the falling edge of the nwait).

According to the spec of EPP the transfer rates should be at least
500Kbytes/sec (up to 2MBytes/sec). What
am I doing wrong here. Is it the standard parport driver? am I missing a

Please help,

Peter van Duijn