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Altera_Forum's avatar
Altera_Forum
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18 years ago

USB Device Controller ISP1362

Hi,

I'd like to ask if anyone knows how to transfer more than 64 kBytes between the Device Controller (in chip ISP1362 placed on my DE2_Board) and the Host controller (my computer).

I'm not able to write more then 64 kbytes into the buffer of the OUT endpoint.

I access the register of the endpoints in PIO mode.

Maybe I have to change the configurations of the 2 endpoints I use, for example to ISOCHRONOUS one (that i don't really know what it is)?

I hope I have been clear enough,

if anyone would give me even a little suggestion it would be a great help for me!

thank you,

Paola

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  • Altera_Forum's avatar
    Altera_Forum
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    18 years ago

    You surely didn't mean 64 kB. Actually the maximum packet size for bulk transfer is 64 byte by USB specification. This isn't a speed limitation, cause multiple packets may be transferred during an USB basic time interval of 1 ms, up to the maximum full speed USB capacity. I'm not particular familiar with ISP1362, but as far as I understand the manual and embedded programming guide, you can place multiple packets into a buffer in advance, as usual with other USB controllers. Bulk transfer is the recommended and most effective method for regular data transfer and e. g. used with mass storage device class (MSC). Isochrone transfer is, as the name suggests, for data that must be delivered continously in time, e. g. audio streams.