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General Discussion / Re: FT232H not seen by Windows 10
« on: April 27, 2021, 04:26:28 PM »
Hello,
It sounds like you are having some custom hardware problems.
If all the parameters in USBView are zero, this points to a hardware issue.
You can send details to your local support team including your hardware schematic:
https://ftdichip.com/technical-support/
We can perform a review of the complete design to look for all issues.
Please see AN_146 USB Hardware Design Guidelines for FTDI ICs.
The USB data lines should have zero to 10ohm resistors for edge rate control.
On our UM232H module, it has 0ohm resistors fitted.
On our UM232H-B module, it has 10ohm resistors fitted.
You can use these known good modules as a reference.
Note that 'SINGLE RS232-HS' is the default description if you do not have an external EEPROM fitted.
This is a High Speed USB device and will operate at USB High Speed.
It can also operate at Full Speed (12Mbits/second).
A full speed USB device (12Mbps) uses a 1k5 pull-up resistor to VCC on the USB DP signal line. This is integrated in the design.
A high speed USB device (480Mbps) will initially appear as a full speed device to the host. The first thing the USB host does is to attempt to send /receive packets at high speed to the USB 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. If this initial communication fails then the USB host assumes that the device is a full speed device.
This means a high speed device has a 1k5 pull up resistor on USB DP that can be switched in / out of circuit.
You can’t control Full / High Speed operation in the IC.
Best Regards,
FTDI Community
It sounds like you are having some custom hardware problems.
If all the parameters in USBView are zero, this points to a hardware issue.
You can send details to your local support team including your hardware schematic:
https://ftdichip.com/technical-support/
We can perform a review of the complete design to look for all issues.
Please see AN_146 USB Hardware Design Guidelines for FTDI ICs.
The USB data lines should have zero to 10ohm resistors for edge rate control.
On our UM232H module, it has 0ohm resistors fitted.
On our UM232H-B module, it has 10ohm resistors fitted.
You can use these known good modules as a reference.
Note that 'SINGLE RS232-HS' is the default description if you do not have an external EEPROM fitted.
This is a High Speed USB device and will operate at USB High Speed.
It can also operate at Full Speed (12Mbits/second).
A full speed USB device (12Mbps) uses a 1k5 pull-up resistor to VCC on the USB DP signal line. This is integrated in the design.
A high speed USB device (480Mbps) will initially appear as a full speed device to the host. The first thing the USB host does is to attempt to send /receive packets at high speed to the USB 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. If this initial communication fails then the USB host assumes that the device is a full speed device.
This means a high speed device has a 1k5 pull up resistor on USB DP that can be switched in / out of circuit.
You can’t control Full / High Speed operation in the IC.
Best Regards,
FTDI Community