Flash Magic can not communicate P89C61x2BA

[andrewpei]

This is my first time using Flash Magic.
Whenever I start flashmagic,  I get the following error..

"Unable to read the security bits and clocks bit. the security bit and 6clks/cycle may not reflect the actual settings of the device. to read the security and clock bits connect the device to the selected com port and place it into bootrom and then click retry button."


and whn i try to connect ... it says like this
"cannot connect at the specified rate try reduce rate. reset the hardware in isp mode again."

However,  with the same hardwares including the same RS232 cable and another ISP software provided by the hardware manufacture. I download an application software into my target P89C61x2BA successfully.  So I am sure there are no error in hardware design or cable connection.  But I do not know what is the problem and how to resolve it.

My Flash Magic 1.84 setting options is:
COM Port:  Com 2
Baud Rate: 2400(I tried all different Baud rate, the result is the same-failure)
Device: 89C61x2
Oscillator Freq(MHz):11.0592

Could any one help me?
Thanks a lot!

[andrewpei]

I have found the solution!
I re-configured the Advanced-opinon-->hardware config. I check the box "use DTR and RTS to control RST and PSEN" and the box "Keep RTS asserted while COM port open".
But I do not know the meaning of box "Keep RTS asserted while COM port open ". I tried to uncheck this opition, the communication failure come out again.
Who can help me by giving a datailed explaining of this box?

Thanks!

[Andy Ayre]

Keep RTS asserted while the COM port is open does exactly what it says. The COM port is kept open throughout the entire ISP operation being performed.

This feature is useful when you want to power your target hardware from the COM Port - you would connect the RTS line to your power supply. My guess is that in your hardware design you use RTS in such a way that your hardware only functions correctly if RTS is asserted constantly. Something the other ISP software you are using does without telling you.