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Visitor
alexandre.solon
Posts: 11
Registered: ‎11-20-2008
0
Accepted Solution

Uartlite unexpected characters

[ Edited ]

Hello all,

 

 

I am testing some simple examples within Plataform Studio, but xps_uartlite is printing unexpected characters (unreadable).

I have already tried every baud_rate that is possible, between HyperTerminal and uartlite (Spartan3E - MicroBlaze).

 

There are some interesting posts in the forum about the same problem, but none of them were useful. 

 

In the Xilinx answer database there is a similar problem, but the provided solution is also a dead end: http//www.xilinx.com/support/answers/16632.htm

 


Please,

 

Could someone help me?

Message Edited by alexandre.solon on 10-27-2009 09:19 AM
Xilinx Employee
austin
Posts: 3,663
Registered: ‎02-27-2008
0

Re: Uartlite unexpected characters

Alexandre,

 

Are you downloading an existing demo design for a demo pcb (eg ML505, XUP V5 LX110T)?

 

If so, the settings are described in the user's guide, and they do work (at least, whenever I try them, they work just fine).


I suggest if you are not downloading an existing demo design, that you do so.  If it doesn't work, then you should start to check your wiring, and power supplies.

 

If this is your own pcb (not a demo board) then I suggest you start with a simpler design to check out the wiring, voltage levels, etc.

 

 

 

Austin Lesea
Principal Engineer
Xilinx San Jose
Visitor
alexandre.solon
Posts: 11
Registered: ‎11-20-2008
0

Re: Uartlite unexpected characters

Austin,

 

I have just downloaded and tested a xilinx demo for Spartan3E, which outputs some characters through rs232.

The same problem occured. 

 

I guess I will have to check the wiring and power supplies, as you mentioned.

 

Any suggestions?

 

Sorry, I don't have much experencie, yet.

 

Thank you for your reply.

Expert Contributor
prateek_bhatt
Posts: 592
Registered: ‎08-21-2008
0

Re: Uartlite unexpected characters

Hello.

Test your RS232 cable first.

Which version of the tool are you using.

If you are using a version below 10.1 then you should specify correct frequency in the software platform settings as well.

While compiling your software project do you get any warning.

Also check your hardware for any warning after compilation. Not every warning can be ignored. Some warnings are critical.

 

Keep your reference clock and processor bus clock frequency same. Also provide the same in the software platform settings tab.

Kepp your baud rate for hyperterminal and UART same.

In your hyperterminal go to properties and settings and enable echo by clicking the box.

This will tell you what you are sending and what you are receiving. 

Best of luck.
--
Unlimited in my Limits.
Xilinx Employee
austin
Posts: 3,663
Registered: ‎02-27-2008
0

Re: Uartlite unexpected characters

pb,


He downloaded the demo, so he had no choices, other than to connect it properly, and setup Hyperterminal properly.

 

Oh, and set any jumpers properly on the demo board:  he should make sure none have fallen off, or were set to a wrong (different) setting.

 

He should concentrate on making sure his cables are good (he hasa a valid ground connection is a common error:  a missing ground could do what he is seeing).

 

Number of stop bits (1), baud rate (9600), are the only things needed in the hyperterminal program, perhaps also with "no flow control" and ignoring DTR, CTS, etc. (no hardware flow control, either).

 

Austin Lesea
Principal Engineer
Xilinx San Jose
Visitor
alexandre.solon
Posts: 11
Registered: ‎11-20-2008
0

Re: Uartlite unexpected characters

Austin and pb,

 

Thank you very much for replying!

 

I bought another cable and it worked just fine!

 

Sorry for the trouble, but I had a similar problem in the past and it wasn't the cable fault.

 

Once again, thanks a lot!