Strange serial comms issue

[TLSupper]

Hi all,

Any chance you lot can help with this problem?

I'm sending data from a UART onboard an FPGA to COM1 on my XP desktop. It's straight forward, no handshaking etc, 115200 baud communication.

Using MTTTY, I can receive characters sent to the COM port if I disable all flow control options, as expected. However, if I try to receive data with Hyperterminal (again with no flow control), I get nothing at all. I also get nothing if I use the Windows API stuff through C++.

I guess that the same problem is affecting my C++ code and Hyperterminal. I need to eventually get the C++ stuff working, so if anyone can suggest why MTTTY works but Hyperterminal doesn't, I'd be very grateful.

Many thanks,
TLS

[gar]

070926-1641 EST USA

TLSupper:

The problem with high level languages is that you have no idea what is going on as a result of your simple command.

Maybe MTTTY directly accesses the UART.

Try setting the PC UART FIFO to disable in device manager and use hardware handshake with your program or HyperTerminal.

.

[TLSupper]

Hi gar,

Thanks for the suggestion. It turns out the problem was something to do with the cable - I was worried that Hyperterminal might be looking at the control lines so I built a cable with only ground and TX. It works a treat.

Cheers,
TLS