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Message
From: ramachandiran.v@s...<ramachandiran.v@s...>
Date: Sat Jan 15 11:45:01 CET 2005
Subject: [usb] USB 1.1 Device Core Endpoint Clarification
Dear USB People,I have a Question regarding USB 1.1 Endpoint . First Let me describe what I'm doing using USB Core. I developed PS2 Keyboard to USB application using USB 1.1 core. I wrote PS2
Interface logic and gluelogic to store ASCII value of the Pressed Key in Endpoint 5.
[ Endpoint 5 is configured as IN , INTERRUPT with max of 64 Byte transfer. I use
Windriver USB software to read USB Port.
ep5_cfg = `INT | `IN | 14'd0001
Device Enumeration is taking place properly and i could see all the endpoints with the
same setup mentioned in usb1_rom.v file.
The Problem i'm facing is like , what ever the data i type in Keyboard , It is read and
displayed TWICE. I checked the behavioral simulation and saw that the data is stored
in Endpoint FIFO only once with WE for FIFO is kept asserted for 1 Clock Pulse.
I even tried to store the data into Endpoint FIFO continuously and then Invoked
Windriver software. Then also each character is displayed TWICE [ i.e., . i Typed
rama ..But i received as ..rraammaa ].
Is this the Problem with INTERRUPT Transfer Mechanism the way i configred.
or
Could it be the Problem of Windriver Software ?..
Can anyone clarify me where exactly the Problem and how can i overcome this ?
It would be grate Helpful for me.
Thanks in Advance ,
Ramachandiran.V
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