Have you checked the settings for the OPB_UART-component or whatever you use for the RS232? The settings for baudrate, partity and stop bits have to be identical in EDK and Hyperterminal, otherwise it won't work.
Ah, be careful with Hyperterminal, It's not the greatest. Make sure (if this is the case for you) that you have the flow-control set correctly... "None" means that it doesn't use any protocol to ensure the terminals at either end of the line are alive and synchronised etc etc. I normally find this the best way to go. (ie. the only wires used in the cable are Tx and Rx) Also make sure you check the box that says "echo typed characters locally" if you want to see what you're typing. But by far the best is to write a tiny VB script, using MSComm1.OnComm to grab data from the PC UART and send it back. Lets you rapidly develop some interesting debug stuff! HTH Ben
. Unfortunately, it hasn't been updated since 1999 (!), but it works fine under all Windows OSes. The main limitation is that it only knows about Com1:-Com4: .
Personally, I'm surprised Microsoft included the piece of junk that is Hyperterminal in Windows; there were far better choices! I also find it incredible that Hilgraeve had the audacity to stick an advertisement for the full version of their product into it -- yeah, if the stripped-down version works so poorly, I'd really want to risk using a full blown version!
Before you spend too much time screwing around with Hyperterm or other serial programs, have you looked at the signals from your fpga board to the serial input of your computer? Start with no serial cable, and check that the TX pin (when no characters being sent) is -5V to -15V. The RX line should be floating close to 0V. Check the two pins that TX and RX connect to on the computer (pins 2 and 3 of serial port connector). The one that your FPGA TX is going to connect to should be an RX pin, and it should be close to 0V. The pin that the FPGA board's RX is going to connect to (computer TX) should be -5V to -15V.
Then to check that you have hyperterm set up right, with nothing connected to the computer serial port, type on the keyboard. Nothing should appear. Then connect pins 2 and 3 of computers serial port. Now typing should echo.
On your FPGA board, change your program so that it just continuously send a "*" character. Connect a scope to the FPGA board's TX signal. Check the timing makes sense. Do the same on the computer (hold down the "*" key), and look at what the computer is sending out. The characters should look like what you got from the FPGA board.
Until ALL of what I have written above works, there is no point in connecting the FPGA board to the computer, and complaining that it "doesn't work". You need to do the above to localise where the problem is.
I would have fully agreed an hour ago. However, today I was so frustrated about the broken scroll-buffer that I checked Hilgraeves homepage (did anyone other ever did that?): There is a free update ("personal edition") that at least fixes this bug... As I have downloaded it only about 10 minutes ago I do not know about the other bugs, but it can't be worse then before...
BTW: In the XP-HyperTerm there is a note about (C) Microsoft, parts (c) by Hilgraeve, while the update (and I also believe the original Win
95-HyperTerm) is only (c) Hilgraeve. So I get the feeling, that we were all partly blaming the wrong company for that piece of junk ;-)
I can't tell. You listed RX twice, and no TX for the PC :-) The levels you have for the FPGA board is exactly what I wrote you should expect.
If the first one for the PC is really "RX" and the second is "TX", then this is wrong. You have the wrong labels (which is what I guessed was your problem). The PC signal with -15 is a TX pin, not an RX pin.
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