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USB Low-Full-High Speed Peripherals

Anonymous
Not applicable

Hi,everyone,

   

in the enfpoint descriptor, wMaxPacketSize's bit 12:11 is the number of transaction in one microframe for isochrounous endpoint .

   

so what's the connotation of bit12:11 in wMaxPacketSize for a interrupt endpoint? does it have the same meaning? 

   

if so, when i set it to be 0x1c00---3 transactions in one microframe and 1024 maxpacketsize, the interrupt endpoint can't transfer anyword even i use the cyconsole.exe to test.

   

if the wMaxPacketSize's bit 12:11 for interrupt endpoint doesn't has the same connotation as the isochronous endpoiunt, the binterval define the minimum interrupt period as 125us. so 68013's interrupt endpoint  can only transfer one packet  in one microframe. obviously this is not right.

   

so i'm perplexed on the connotation of bit12:11 in wMaxPacketSize for a interrupt endpoint.

   

should somebody tell me? thanks a lot!

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Anonymous
Not applicable

If you send more than 1 packet in the microframe for iso and interrupt they're called high-speed high-bandwidth endpoints and the connotation is the same. How many packets are you trying to transfer and what is the behavior shown by Cyconsole.

   

Have you tried modifying the cystream firmware and have screamer/streamer do the transfer?

   

Regards,

   

Anand

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Anonymous
Not applicable

Hi,Anand,

   

I'd like to send 3 packets in one microframe,

   

In the MaxPacketSize, bit15:13 must be 000b, bit12:11 represent the packets in one microframe, so if I want to transfer 3 packets I would set it to be 11b, bit10:0 represents the maximum size of one packet, if I want the packet size is 1024, so the bit 10:0 should be 10000000000b. so in my case it would be 1c00h.

   

but if i set the MaxPacketSize to be 1c00h in the endpoint descriptor, from the cyconsole.exe i can't  even  see the pipes/endpoints.

   

later on i read the code of cystreamer, it sets the  MaxPacketSize to be 1400h. and it do works well.

   

furthermore, i have read the code of the cystreamer several days ago, then i developed my application software, amazingly the speed  approach 49MB/s with bulk transfer. ^_^

   

so i try to sue it in iso or interrupt transfer, but the interrupt only has 23.2MB/s.

   

anyhow, the 68013 is an excellent chip. ^_^

   

Best regards,

   

FuChy Ian

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Anonymous
Not applicable

Even though iso and interrupt endpoint have guaranteed bandwidth you would be able to get a maximum of around 24 MB/s only per endpoint (limited by spec). Bulk on the other hand doesn't have guaranteed bandwidth but as long as the USB doesn't have too many devices connected you should be able to speed around 48MB/s. Maximum possible for Bulk as per spec is 53MB/s (taking overhead into account) but most controller can't transfer this much.

   

Regards,

   

Anand

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Anonymous
Not applicable

Hello,Anand,

   

I know that the transfer theory about the iso and interrupt, and also the highest theoretical speed is 53.248MB/s.

   

I'm perplexed on the maxpacketsize in 68013. Although it matters little, I am still would like to grasp it.

   

Best regards,

   

Fuchy Ian

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Anonymous
Not applicable

Please clarify your doubt regarding the maxpacketsize of cy7c68013 so that I can clear it.

   

Regards,

   

Anand

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Anonymous
Not applicable

I'd like to send 3 packets in one microframe,

   

In the MaxPacketSize, bit15:13 must be 000b, bit12:11 represent the packets in one microframe, so if I want to transfer 3 packets I would set it to be 11b, bit10:0 represents the maximum size of one packet, if I want the packet size is 1024, so the bit 10:0 should be 10000000000b. so in my case it would be 1c00h.

   

but if i set the MaxPacketSize to be 1c00h in the endpoint descriptor, from the cyconsole.exe i can't  even  see the pipes/endpoints.

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Anonymous
Not applicable

00 is for 1 packet per microframe

   

01 is for 2 packets per microframe

   

10 is for 3 packets per microframe

   

Regards,

   

Anand

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