Alex <[email protected]> writes:

> The FPGA supplies serial output data using LVTTL or LVCMOS levels to
> the Maxim device, which in turn, converts the logic value to the
> appropriate RS-232 voltage level. Likewise, the Maxim device
> converts the RS-232 serial input data to LVTTL levels for the FPGA.
> A series resistor between the Maxim output pin and the FPGA¢s RXD
> pin protects against accidental logic conflicts.

> I am really puzzled!

Why? What you quoted does not mention a UART, what they describe is a
bog standard level shifter. I'm not sure if my board is the same as
yours, I have a "Spartan 3E 1600 Board" from Digilent, but I think
it's the same. The schematic for it shows a MAX3232 connected to the
serial ports, which is exactly that, a level shifter. Not a UART.