| ??? 12/05/08 12:16 Modified: 12/05/08 12:36 Read: times |
#160645 - Any other USB device on the bus? Responding to: ???'s previous message |
the ft245 datasheet says that the throughput is 1 MB/Sec! Not always. FT245(Bx / R) carries the main data stream over bulk transfer. If any other USB device shares the same bus tree, it may disturb the speed of FT245. Check the bus tree using USBView MS USBView on FTID utility page http://www.ftdichip.com/Resources...sbview.zip Any other device, except for hub(s), under the host controller to which the FT245 connects? For example, USB mouse and keyboard. If you have a USB2.0 hub (hi-speed), connect it to the PC. and connect just the FT245 to the hub, without any other USB device. PC USB port --- USB2.0 hub --- FT245 This connection moves the FT245 under EHCI (hi-speed) host controller, and isolates the device from other full-/low-speed device. P4 with cpu speed grade 2.4 GHz It's enough for full-speed. Tsuneo |
| Topic | Author | Date |
| CCD Reader Project Problem! | 01/01/70 00:00 | |
| Faster PC? | 01/01/70 00:00 | |
| P4 | 01/01/70 00:00 | |
| Re:P4 | 01/01/70 00:00 | |
| Any other USB device on the bus? | 01/01/70 00:00 | |
| Missing data even for true raw rate requirement | 01/01/70 00:00 | |
| Not enough information for a diagnosis | 01/01/70 00:00 | |
Buffer size on the PC device driver | 01/01/70 00:00 |