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rs232-DCE connection on TE0304 with TE0630

Started by a3an, March 11, 2012, 03:45:05 AM

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a3an

I am trying to figure out which FPGA pins (TE0630) are connected to TxD-DCE and RxD-DCE on a TE0304 demo carrier. The TE0304 user guide suggests P6 and R6, presumable for a TE0300 board. I guess it should be AB15 and Y15 on a TE0630 board. Is this assumption correct ?

Oleksandr Kiyenko

Hello a3an,
TE0630 have different net naming and connection.
For TE0630 with TE0304 we have

TE0304  connector  TE0630 net    TE0630 FPGA pin
Rx-DCE --- J5-29 --- V2_IO_02_P --- Y7
Tx-DCE --- J5-31 --- V2_IO_02_N --- AB7

Regards,
Alex

a3an


JS

I have also a problem with that RS 232 port using TE 630 & TE0304

For RS-232 DCE Port, which is obviously the one in the middle, the manual says:

Pin 2      Out   TxD-DCE      AB 7
Pin 3      In      RxD-DCE     Y 7

For RS-232 DCT Port, which is obviously the one in the side, the manual says:

Pin  2    In       RxD-DTE    AA8
Pin  3    Oout  TxD-DTE     U8

I tried both but cannot get access. I cannot even scan the input pin with Chip Scope. The Inputs are always high. I am using a USB to Serial Converter which obviously works, when I short cut it with a cross over cable. It has two channels and sending / receiveing in both direction work.

Short Cutting the path inside the FPGA by wiring RX to Tx directly does not work.

Is it possible that there is a level or impedance issue?  What voltage is required to drive the pin?

The TE0304 is powered by 2.5mm 5V and operates well, that means the FPGA is e.g.able to drive VGA video with.

I thought of a defective chip already but the "1" at the input seems to come from the Chip, since there is no  pullup in the FPGA.

Any idea?






JS

I still have no input or output.

Is it possible that there is a misconfiguration regarding power?

I am powering via extern adapter and found, that there are powering options for bank 0 (?)
In the manual it says, that R102 / R103 schould (not) be populated - what is the case with my module.

What about the DIP switch?
Which is  the right configuration to power the banks correctly?





Oleksandr Kiyenko

Hello Jürgen

There is not power problem because UART pins are from FPGA Bank 2, which have fixed 3.3V VCCIO. Can you check signal directions for your system, maybe you need other type of cable.

Best regards
Oleksandr Kiyenko

JS

Yes, I have seen that too.  The cable seems ok, but I am going to test with another board so see if the adapter is the problem. It is a common FTDI noname, who knows. thx