Hello, I'm using the T89C51RD2 micro with RTX51-full RTOS. I need to count number of passed minutes and I want to know what is the prefered way to do it. According to the user manual and data sheet the built-in UART requires 32 clock cycles (from timer 2) for each bit (of the received byte). Because the code timed an 8 bits, the value that will be needed for init the time in auto-reload mode is calculated by dividing the CPU cycle count by 32*8=256. According to this information with a frequency of 11.0592MHz and time slice of 25msec (os_set_slice(23040)) I can wait 5 seconds max (os_wait(K_IVL, 200, 0);). Now I thought about several options: Option 1 – Write "os_wait(K_IVL, 200, 0);" line 12 times (5sec*12=1minute). Option 2 – Write "os_wait(K_IVL, 200, 0);" line in "for" loop that count to 12. Which of them is better? Are there's any other way to do it? Thanks a lot, Roberto.