VIII - 9Chapter 8 Time Base Timer / 8-bit Free-running Timer8-bit Free-running TimerCount Timing of Timer Operation (Timer 6)Binary counter counts up with the selected clock source as a count clock.(A) When any data is written to the compare register as the TM6CLRS flag is "0", the binarycounter is cleared to x'00'.(B) Even if any data is written to the compare register as the TM6CLRS flag is "1", the binarycounter is not changed.(C) When the binary counter reaches the value of the compare register as the TM6CLRS flag is"1", an interrupt request flag is set at the next count clock.(D) When an interrupt request flag is set, the binary counter is cleared to x'00' and restarts thecounting.(E) Even if the binary counter reaches the value of the compare register as the TM6CLRS flag is"0", no interrupt request flag is set.Figure 8-3-2 Count Timing of Timer Operation (Timer 6)M N M0101 02 N-1 N02/00 00 01Count clockTM6CLRSflagCompareregisterBinarycounterInterruptrequestflag02 03 M-1 M 00 01(A)(C)(D)(B)(E)If the compare register is set the smaller than the binary counter during the count operation,the binary counter counts up to the overflow, at first.If fx is selected as the count clock source in timer 6, when the binary counter is read atoperation, uncertain value on counting up may be read. To prevent this, select the synchro-nous fx as the count clock source.But if the synchronous fx is selected as the count clock source, CPU mode cannot returnfrom STOP/HALT mode.When the binary counter reaches the value in the compare register, the inrerrupt request flagis set and the binary counter is cleared, at the next count clock.So, set the compare register as :Compare register setting = (count till the interrupt request - 1)
