Hi,
I am trying to do a 8-bit X 16-bit multiplication on the FG4618 using IAR compiler.
My code goes something like this:
Z = Y * 0x3E8
where Z is of type DWORD and Y is of type BYTE
For all values of Y upto 0x1F, I get correct results.
However, if I change the value of Y to 0x20 or above, I get a strange result, something like 0x2F90E30.
I checked the disassembly for this in the debugger and it generates correct assembly code for values of Y upto 0x1F. But for anything equal to 0x20 and above, the assembly code goes haywire.
I am really confused! I tried including "math.h", but it did not help.
I tried doing Z = (Y << 0x0A) and I get the same result.
I can use the hardware multiplier to do this and I might get the correct result, but I dont understand why doesnt the compiler do it correctly.
Am I missing out on something? Can someone please help me on this!!!
With Thanks and Regards,
Tushar
