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We have a strange problem.
The system running under QNX 4.25 RTOS in PC H/W platform. The
> application software connects to a number of devices (card readers)
> through RS 422 port. The transmission is at 9600 baud. The system runs
> perfectly with old PC (up to Pentium 3 PC). When the same application
> software is run in Pentium 4 based PC (2.6GHz - 3 GHz), it is observed
> that for lower system clock (2.6 GHz) the application software
> communicates to serial card readers without any problem.
>
> When connected in Petium 4 PC (3 GHz) with higher PCI clock, it is
> observed that application software terminates after indicating
> ''''Memory Fault'''' (SIGSEGV), at memory xxxx:xxxx.
> It is observed that
> if we remove the Ethernet Networking card from PCI slot 1 and place
> the
> CP-132 in that slot and donot put the Ethernet card, the system donot
> give any memory fault. However, it does not carry out any serial
> communication function (both transmission and reception).
>
> It is to be mentioned here, for lower speed PC, the serial card is not
> slot dependant, whereas for higher speed PC, the serial card work only
> in specific slot (slot 1). The size of RAM in lower speed PC is also
> less (256MB). It is found from BIOS setup that 2.66GHz PC is having
> DRAM frequency of 100MHz whereas for 3 GHz PC, the system frequency is
> 800MHz and System Memory speed is 266 MHz.

Can anybody give some clue to this problem? How to solve this problem?
Thanks in advance.

--- update: In Pentium 4, 3 GHz machines, the PCI card work when put in one specific slot (in one m/c slot 3), the application program does not terminate with Memory fault (mentioned above) - but does not carry out any communication. In other slots, the application program terminates indicating Memory Fault. There is no other card present in the system.

Thanks in advance.

Ranajit Kumar


R kumar