On 2 фев, 09:14, glen herrmannsfeldt <g...@ugcs.caltech.edu>wrote:
> Alex <vict...@gmail.com> wrote:
> > I have started using Xilinx Spartan3E 1600E Microblaze Development
> > Board and want to use its RS232 facility in my project. This board has
> > two RS232 connectors but I cannot figure out what UART it uses. I was
> > searching for UART chip on the board (I was actually searching for a
> > MAXIM chip) and have seen none.
>
> It would be unusual to put a UART on an FPGA development board.
>
> You should implement one in the FPGA logic.
>
> -- glen

I also had this thought until had noticed that MAXIM UART device is
mentioned on page 61 of ug257:

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!