Assign register value to variable

[artvolk]

Posted on June 06, 2011 at 21:05

Good day!

I'm trying to assign register value to a variable in COSMIC C. I've tried the obvious way first, but it doesn't work: uint8_t test = 0; ... test = CLK->SWCR; // define from stm8s.h and uint8_t test = 0; ... test = CLK_SWCR; // define from ''C:\Program Files\COSMIC\CXSTM8_32K\Hstm8\iostm8s.h'' When I run my program in Debug mode and create a watch for 'test' variable it is always zero. What can be wrong? Thanks in advance!

[luca239955_stm1_st]

Posted on June 07, 2011 at 08:31 Hi, one possibility is that your variable ''test'' is optimized away: declare it volatile as a minimum. Also check that the hardware register you are reading does not actually contain zero. Hope it helps. Luca

[artvolk]

Posted on June 07, 2011 at 22:54

Thank you a lot, it seems it was really optimized, despite it was builded in Debug mode.

'volatile' does the trick, thanks a lot!