On Fri, Jul 15, 2011 at 10:28 PM, Laurent Gauch <laurent.ga...@amontec.com> wrote: > Xiaofan Chen wrote:
>>> I think Freddie is probably right. There is still a bit of speed bump >>> compared to the >>> on-board ftdi2232C based Luminary-ICDI interface. >>> >>> jtag_khz = 1200 KHz, 11.820 KiB/s versus 11.016 KiB/s >>> jtag_khz = max supported, 12.729 KiB/s versus 11.524 KiB/s (10% faster) >>> >> >> For the USB 2.0 Jtagkey2, using the WHQL driver and ftd2xx is >> only about 5% faster than using libftdi and libusb-win32 filter driver >> on top of the WHQL driver. >> >> jtag_khz = 1200 KHz, 11.826 KiB/s (ftd2xx) versus 11.296 KiB/s >> (libftdi), (4.7% faster) >> jtag_khz = 3000 KHz, 12.729 KiB/s (ftd2xx) versus 12.096 KiB/s >> (libftdi), (5.2% faster) >> >> Probably I will try another target to see the flash download speed >> difference. I think Freddie is right that the speed is rather limited by the Flash. > On a USB 2.0 High-Speed port or under USB HUB full-speed ? On a USB 2.0 High-Speed port. This is with a 3-year old PC running Windows 7 Ultimate 32bit (Core 2 Duo E4700, 2GB RAM). Output from USBView. http://www.ftdichip.com/Support/Utilities.htm Take note of the "Device Bus Speed: High" and the fact that bulk endpoint size is 512B. Device Descriptor: bcdUSB: 0x0200 bDeviceClass: 0x00 bDeviceSubClass: 0x00 bDeviceProtocol: 0x00 bMaxPacketSize0: 0x40 (64) idVendor: 0x0403 (Future Technology Devices International Limited) idProduct: 0xCFF8 bcdDevice: 0x0700 iManufacturer: 0x01 iProduct: 0x02 iSerialNumber: 0x03 bNumConfigurations: 0x01 ConnectionStatus: DeviceConnected Current Config Value: 0x01 Device Bus Speed: High Device Address: 0x01 Open Pipes: 4 Endpoint Descriptor: bEndpointAddress: 0x81 IN Transfer Type: Bulk wMaxPacketSize: 0x0200 (512) bInterval: 0x00 Endpoint Descriptor: bEndpointAddress: 0x02 OUT Transfer Type: Bulk wMaxPacketSize: 0x0200 (512) bInterval: 0x00 Endpoint Descriptor: bEndpointAddress: 0x83 IN Transfer Type: Bulk wMaxPacketSize: 0x0200 (512) bInterval: 0x00 Endpoint Descriptor: bEndpointAddress: 0x04 OUT Transfer Type: Bulk wMaxPacketSize: 0x0200 (512) bInterval: 0x00 -- Xiaofan _______________________________________________ Openocd-development mailing list Openocd-development@lists.berlios.de https://lists.berlios.de/mailman/listinfo/openocd-development
