zittix
Joined: 27 Jul 2006 Posts: 1
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Very low speed issue with CCS USB Stack |
Posted: Thu Jul 27, 2006 11:59 am |
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Hi everybody,
I'm trying to develop an USB<->LCD adapter for an SED1335-based lcd...
I'm using USB-bulk mode at full speed.
My pic is clocked at 48 Mhz!
My code look like the usb_scope example provided with the compiler.. I get 64-byte from the bulk endpoint and then I send byte per byte the data to the lcd.
Transfer PIC to LCD is very fast (about 10 ms for 9600 bytes) but USB to PIC (and USB to LCD) takes very very long! I have to wait about 300 ms for 9600 bytes!
USB Full speed should have a trasnfer rate of 12 Mbps ! I don't want this powerfull rate but 1 or 2 Mbps should be great for me...
Anyone has the same problem ? Is a CCS USB Stack problem or is it an hardware problem ? Should I use the microchip USB stack ?
Thanks in advance,
Best regards
Mathieu |
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