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TotalFifoSize in STM32f107

Question asked by The Boat on Oct 17, 2011
I have been looking at the USB OTG Libraries for the 105/7 and I've come across the variable  TotalFifoSize.  It's set to 320, when using the Full speed core.

I was wondering if anyone knew if this was because of a hardware spec, that I can't seem to find, or if it is a choice made by the libraries, and if it is a choice, what are some of the reasons one might consider when making that choice.

The value is set to 320 in the file usb_core.c around line 234. 

snippet of usb_core.c:
.....
 /* initialize device cfg following its address */
  if (coreID == USB_OTG_FS_CORE_ID)
  {
    baseAddress                = USB_OTG_FS_BASE_ADDR;
    pdev->cfg.coreID           = USB_OTG_FS_CORE_ID;
    pdev->cfg.host_channels    = 8 ;
    pdev->cfg.dev_endpoints    = 4 ;
    pdev->cfg.TotalFifoSize    = 320; /* in 32-bits */
    pdev->cfg.phy_itface       = USB_OTG_EMBEDDED_PHY;     
    ....

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