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<?xml-stylesheet type="text/xsl" href="https://community.arm.com/utility/feedstylesheets/rss.xsl" media="screen"?><rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:slash="http://purl.org/rss/1.0/modules/slash/" xmlns:wfw="http://wellformedweb.org/CommentAPI/"><channel><title>Slow enumeration for USB 2.0 full speed device.</title><link>https://community.arm.com/developer/tools-software/tools/f/keil-forum/24319/slow-enumeration-for-usb-2-0-full-speed-device</link><description> 
Hello, 

 
I have LPC2368 controller which supports USB 2.0 full speed
device. 

 
While enumeration, I noticed the below request sequence 
from Host to device: 

 
1. Device Descriptor 
2. Set Address 
3. Device Descriptor 
4. Device Configuration</description><dc:language>en-US</dc:language><generator>Telligent Community 10</generator><item><title>RE: Slow enumeration for USB 2.0 full speed device.</title><link>https://community.arm.com/thread/135606?ContentTypeID=1</link><pubDate>Mon, 08 Dec 2008 17:55:38 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:9197e946-4a5c-4b9f-9c0e-dd7c15195785</guid><dc:creator>Tsuneo Chinzei</dc:creator><description>&lt;p&gt;&lt;p&gt;
&lt;i&gt;&amp;quot;the stall command from device reaches host after 5
seconds.&amp;quot;&lt;/i&gt;&lt;/p&gt;

&lt;p&gt;
In our device, bus analyzer shows that STALL is issued by the
device at the IN transaction just after the SETUP which specifies
Get_Descriptor( Device Qualifier ). The interval is just one frame (1
ms) - I observed it on UHCI controller.&lt;/p&gt;

&lt;p&gt;
If it takes so long, the device respond nothing to the IN
transaction(s), and the host repeats SETUP again and again (up to
three times).&lt;/p&gt;

&lt;p&gt;
Maybe the firmware doesn&amp;#39;t set STALL to the engine correctly.&lt;/p&gt;

&lt;p&gt;
&lt;i&gt;&amp;quot;we got the client code from LPC&amp;quot;&lt;/i&gt;&lt;/p&gt;

&lt;p&gt;
What do you mean LPC?&lt;br /&gt;
LPCUSB by Bertrik?&lt;/p&gt;

&lt;p&gt;
Tsuneo&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: Slow enumeration for USB 2.0 full speed device.</title><link>https://community.arm.com/thread/125113?ContentTypeID=1</link><pubDate>Mon, 08 Dec 2008 16:41:27 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:2b99ae54-b1b0-4734-ac8b-a8653260c8e1</guid><dc:creator>VAIGO G</dc:creator><description>&lt;p&gt;&lt;p&gt;
Thanks for your reply.&lt;/p&gt;

&lt;p&gt;
I&amp;#39;ve made many full-speed devices assigned to USB2.0, I&amp;#39;ve never
seen WinXP SP2 delays the enumeration of these devices. It&amp;#39;s most
likely the firmware side problem.&lt;/p&gt;

&lt;p&gt;
==&amp;gt; We checkced with the USB analyzer, the stall command from
device reaches host after 5 seconds. I believe this could be the main
reason for the delay.&lt;/p&gt;

&lt;p&gt;
Are you using a USB ARM example from KEIL as the base code?&lt;br /&gt;
OR did you make your code from scratch by yourself?&lt;br /&gt;
In the first place, which MCU or USB peripheral are you using?&lt;/p&gt;

&lt;p&gt;
==&amp;gt; We are using LPC2368 controller and we got the client code
from LPC.&lt;/p&gt;

&lt;p&gt;
Thanks&lt;br /&gt;
VAIGO&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: Slow enumeration for USB 2.0 full speed device.</title><link>https://community.arm.com/thread/114491?ContentTypeID=1</link><pubDate>Mon, 08 Dec 2008 06:51:43 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:9ef1bb3a-73f3-45e1-b97d-02a66d6db421</guid><dc:creator>Tsuneo Chinzei</dc:creator><description>&lt;p&gt;&lt;p&gt;
When you specify USB1.1 (0x0110) on the bcdUSB field of the device
descriptor, the host PC doesn&amp;#39;t issue Get_Descriptor( Device
Qualifier ) request any more. This request is issued just when USB2.0
(0x0200) is assigned to the bcdUSB field AND when the device is
directly connected to the PC without any hub.&lt;/p&gt;

&lt;p&gt;
I&amp;#39;ve made many full-speed devices assigned to USB2.0, I&amp;#39;ve never
seen WinXP SP2 delays the enumeration of these devices. It&amp;#39;s most
likely the firmware side problem.&lt;/p&gt;

&lt;p&gt;
&lt;i&gt;&amp;quot;b) Which example are you making up your device on?&lt;br /&gt;
==&amp;gt; Sorry, I didn&amp;#39;t get your point. Could you please explain about
it.&amp;quot;&lt;/i&gt;&lt;/p&gt;

&lt;p&gt;
Are you using a USB ARM example from KEIL as the base code?&lt;br /&gt;
OR did you make your code from scratch by yourself?&lt;br /&gt;
In the first place, which MCU or USB peripheral are you using?&lt;/p&gt;

&lt;p&gt;
Tsuneo&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: Slow enumeration for USB 2.0 full speed device.</title><link>https://community.arm.com/thread/101417?ContentTypeID=1</link><pubDate>Sun, 07 Dec 2008 18:20:05 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:b555fbad-883e-4529-9427-6a06925f60c5</guid><dc:creator>VAIGO G</dc:creator><description>&lt;p&gt;&lt;p&gt;
We used the same client device source code for 1.1 and 2.0. The
only difference made was, the protocol version in device
descriptor.&lt;/p&gt;

&lt;p&gt;
1) DO we need to make any other change in client side?&lt;br /&gt;
2) On changing the protocol version from 1.1 =&amp;gt; 2.0, the
performance of data transfer better between PC and Client. At the
same time the performance is slows down little with 1.1.&lt;/p&gt;

&lt;p&gt;
Does any body has idea, why it happens like the above.&lt;/p&gt;

&lt;p&gt;
On trying to improve the data transfer, we end up with slow
enumeration.&lt;/p&gt;

&lt;p&gt;
Thanks&lt;br /&gt;
VAIGO&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: Slow enumeration for USB 2.0 full speed device.</title><link>https://community.arm.com/thread/76951?ContentTypeID=1</link><pubDate>Sun, 07 Dec 2008 16:37:57 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:3113bf11-a235-43bc-ab40-ec703d36bc7a</guid><dc:creator>VAIGO G</dc:creator><description>&lt;p&gt;&lt;p&gt;
Hello,&lt;br /&gt;
Thanks for your reply.&lt;/p&gt;

&lt;p&gt;
It should be clarified if this problem is caused by the device
side or the PC side.&lt;br /&gt;
==&amp;gt; I believe the problem is from PC side, since device waiting
for response.&lt;/p&gt;

&lt;p&gt;
a) Which OS are you working on? Windows? XP or Vista? Which
SP?&lt;/p&gt;

&lt;p&gt;
==&amp;gt; I use WINDOWS XP and SP2&lt;/p&gt;

&lt;p&gt;
b) Which example are you making up your device on?&lt;br /&gt;
==&amp;gt; Sorry, I didn&amp;#39;t get your point. Could you please explain about
it.&lt;/p&gt;

&lt;p&gt;
Note: If we are passing 1.1 as protocol version, the enumeration
is happening quickly.&lt;/p&gt;

&lt;p&gt;
Thanks&lt;br /&gt;
VAIGO&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: Slow enumeration for USB 2.0 full speed device.</title><link>https://community.arm.com/thread/53012?ContentTypeID=1</link><pubDate>Fri, 05 Dec 2008 02:06:51 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:840bb01c-3be4-4d83-b230-b5f24f3884c9</guid><dc:creator>Tsuneo Chinzei</dc:creator><description>&lt;p&gt;&lt;p&gt;
&lt;i&gt;&amp;quot;Since my device is 2.0 full speed device so I returned request
error by setting status to STALL for Device Qualifier
request.&lt;/i&gt;&lt;/p&gt;

&lt;p&gt;
It&amp;#39;s fine. Supposed response.&lt;/p&gt;

&lt;p&gt;
&lt;i&gt;&amp;quot;But the problem I am facing is, that the device receives next
request(i.e step 9 string descriptor) after a delay of 4-5
seconds.&amp;quot;&lt;/i&gt;&lt;/p&gt;

&lt;p&gt;
It should be clarified if this problem is caused by the device
side or the PC side.&lt;br /&gt;
a) Which OS are you working on? Windows? XP or Vista? Which SP?&lt;br /&gt;
b) Which example are you making up your device on?&lt;/p&gt;

&lt;p&gt;
Tsuneo&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item></channel></rss>