Accessing VI_PXI_BAR0_SPACE of PXI device

[okisir]

Hi,

I am trying to read/write VI_PXI_BAR0_SPACE of PXI device using with VISA library. Here is sample C code how read data from BAR0 memory.

Spoiler

ViStatus res;
ViSession defaultRM, vi;
ViUInt32 oldData, newData;


viOpenDefaultRM(&defaultRM);
viOpen(defaultRM, "PXI0::CHASSIS1::SLOT3::FUNC0::INSTR",VI_NULL,VI_NULL, &vi);

//READ DATA
ViAddr addr = 0x8000;
viIn32(vi, VI_PXI_BAR0_SPACE, adr, &oldData);
printf("Addr: %04x Data:%08x\n", adr, data);

//WRITE DATA
newData = 0x7FF7;
res = viOut32(vi, VI_PXI_BAR0_SPACE, adr, newData);

This reading part is working without any issue. oldData = 0x7FFC.

I try to write newData = 0x&7FF7.

Something unexcpexted happen.I read data back i got = 0x7FF4.

looks like oldData and newData is logical AND somehow.

Does anyone have experience with reading/writing register BAR0 register map?

Thanks