Dear All
I want to implement USB controller on xilinx/ altera FPGA,
my question is-

1. is it possible to directly connect USB data+ and data- pin to FPGA ?
2. is there any additional interface IC needed to achieve the same?

Regards

Preet

You might need some passive components, such as a series resistor or parallel capacitor. I'm sure it depends upon the specific FPGA chip that you select, particularly the characteristics of its I/O pins. Even on the same chip, not all I/O pins have the same characteristics.

In addition, you might want USB isolation, although that is somewhat rare. Isolation chips are available, and they often incorporate the passive components that I mentioned above, meaning that you would not need anything but the USB jack, isolation chip, and FPGA pins.

I suggest that you study the USB specifications that are freely available online, and compare them to the FPGA chip that you have selected for your design.

You can have an electrical interface externally to the FPGA. This will give you the correct electrical specifications of your interface

An option is to use the USB1T11 chip.

/Michael Unneback

thanks for the replies,

could i use differential pin of any fpga as D+ and D-

Regards

Preet

My quick guess is no, because there are some states of USB which violate the differential conventions. At the very least, you would need to connect D+ and D- to both a pair of differential inputs AND another pair of generic I/O so that you can read the non-standard states at specific times.

only HSIC interface support direct DP/DM. but still in FPGA not possible to achive 480 MBps data rate...for SOC level with HSIC interface you can directly use DM/DP with some external Pull Up/Pull Down.

ISP1504 PHY is best solution for altera FPGA board USB design.

Best Regards:

Ravi Chovatiya