I mean, the same unit and the same cable works OK on some hosts (a Windows 8.1 workstation, a Windows 10 laptop, a Windows 7 laptop) but fails on others (another Windows 8.1 workstation, a Windows XP laptop)Ĭan anybody throw any light about what could be happening? I totally ran out of ideas. The thing is, the board successfully appears as Virtual COM when connected with some PCs but it doesn't with others (where the enumaration phase fails). From there, we successfully built the CDC example.
To do so, first I have build the USB library for this MCU (I cloned the provided usbd_sdk_frdmkl27z_mqx library and followed the attached guide in this post: Re: USB CDC on KL27 processor ).
Usbvision windows 7 full#
You can’t control Full / High Speed operation in the IC.I'm trying to run the USB CDC virtual com example that comes in KSDK 1.2 on a custom board with the KL27 MCU (MKL27Z256VFM4) This means a high speed device has a 1k5 pull up resistor on USB DP that can be switched in / out of circuit. If this initial communication fails then the USB host assumes that the device is a full speed device. This is known as J and K chirp and if communication is successful it will be assumed that the USB device is a high speed device. The first thing the USB host does is to attempt to send /receive packets at high speed to the USB device. This is integrated in the design.Ī high speed USB device (480Mbps) will initially appear as a full speed device to the host. It can also operate at Full Speed (12Mbits/second).Ī full speed USB device (12Mbps) uses a 1k5 pull-up resistor to VCC on the USB DP signal line. This is a High Speed USB device and will operate at USB High Speed. Note that 'SINGLE RS232-HS' is the default description if you do not have an external EEPROM fitted. You can use these known good modules as a reference.
On our UM232H-B module, it has 10ohm resistors fitted. On our UM232H module, it has 0ohm resistors fitted. The USB data lines should have zero to 10ohm resistors for edge rate control. Please see AN_146 USB Hardware Design Guidelines for FTDI ICs. We can perform a review of the complete design to look for all issues. You can send details to your local support team including your hardware schematic: If all the parameters in USBView are zero, this points to a hardware issue. It sounds like you are having some custom hardware problems. the descriptor string of FT232H on FT-Prog is "USB SERIAL" where in USBView and in Devices/Printers is "SINGLE RS232-HS".Ĭan someone give me some pointers about this problem? I also saw that the info in FT-Prog were different from those in USBView (e.g. Usb descriptors change in a coherent way (being it a different chip) aside, maybe, from power demand, where FT232BL presents itself as bus/self powered with 90mA and FT232H as bus powered with 500mA. Opening the device I saw the EEPROM was not implemented, so the FT232H runs its default mode. One thing i noticed is the FT232H converter could not be programmed, FT-Prog says something like "Can't program, device removed?". On the other hand, on a Windows 7 machine, the device is correctly detected by Windows and all the other applications. Unfortunately all the parameters of this random popping device are zero, so it's not very useful. The only sign that the converter is plugged in can be found in USBView, where, if continuously refreshing, sometimes a "USB Streaming" appears in the position where the converter is plugged. It's used as USB-232 interface and lately we started to have problems on Windows 10 machines: the device is totally not detected (no "usb inserted sound", no changes in Device Manager, no device detected in FT-Prog).
0 kommentar(er)
