Hi all,
I found a EPP timeout problem.
I get one byte lost whenever an epp timeout occur
and in the same time a byte is ready by out peripheral.
Normal EPP read cycle. (see EPP_1.tif)
/WRITE: ---------------------------------------
/DATA-STROBE : ---\_____________/---------------------
/WAIT: _______/------------\__________________
/DATA: XXXXXXXDDDDDDDDDDDDDDXXXXXXXXXXXXXXXXXX
|
|Read
problem case: (see EPP_1.tif)
| |
/WRITE: -------...------------------
/DATA-STROBE : ---\___...____/-------------
/WAIT: _______...___/---\__________
/DATA: XXXXXXX...XXXDDDDDXXXXXXXXXX
/INT (Data Ready): _____________/---\__________
| |
| EPP read timeout !!!
| peripheral read cycle
(this byte is lost)
Does anyone has a idea for solving this problem?
Is this a bug in the EPP kernel driver?
My only solution is to add some (INT)-Line check before
the epp read access.
Normally the EPP host hardware could check the (WAIT) -line,
after rising the (/DATA-Strobe) line when a timeout occur?!
Regards
Maik Scholz
<<EPP_1.TIF>> <<EPP_2.TIF>>
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Dipl.-Ing. (FH) Maik Scholz Robert Bosch GmbH
CM/CR-EES3
Phone: (+49) 5121 49 5391 P.O.Box 77 77 77
Fax: (+49) 5121 49 17 5391 D-31132 Hildesheim
mailto:Maik.Scholz@de.bosch.com
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