<< Previous | Next >>

tm_wr

int tm_wr( struct tm * t );

Description

Sets the system time from a tm struct. It is important to note that although tm_rd() reads the SEC_TIMER variable, not the RTC, tm_wr() writes to the RTC directly, and SEC_TIMER is not changed until the program is restarted. The reason for this is so that the DelaySec() function continues to work correctly after setting the system time. To make tm_rd() match the new time written to the RTC without restarting the program, the following should be done:

   

tm_wr(tm);
SEC_TIMER = mktime(tm);

But this could cause problems if a waitfor(DelaySec(n)) is pending completion in a cooperative multitasking program or if the SEC_TIMER variable is being used in another way the user, so user beware.

Parameters

t

Pointer to structure to read date and time from.

struct tm {
char tm_sec;     // seconds 0-59
char tm_min;     // 0-59
char tm_hour;    // 0-23
char tm_mday;    // 1-31
char tm_mon;     // 1-12
char tm_year;    // 80-147 (1980-2047)
char tm_wday;    // 0-6 0==Sunday
};

Return value

 0: Success .
-1: Failure.

Library

RTCLOCK.LIB

See also

mktm, mktime, tm_rd