CHAPTER 7 8-BIT TIMER 80User’s Manual U16898EJ3V0UD1287.5 Notes on 8-Bit Timer 80(1) Error when timer startsThe time from starting the timer to generation of the match signal includes an error of up to 1.5 clocks. This isbecause, if the timer is started while the count clock is high, the rising edge may be immediately detected andthe counter may be incremented (refer to Figure 7-6).Figure 7-6. Case Where Error of 1.5 Clocks (Max.) Occurs8-bit timer counter 80(TM80)Count pulseClear signalSelected clockTCE80Delay ADelay BSelected clockTCE80Clear signalCount pulseTM80 count value 00H 01H 02H 03H ...Delay ADelay BIf the timer is started when the selected clock is highand if delay A > delay B, an error of up to 1.5 clocks occurs.(2) Setting of 8-bit compare register 808-bit compare register 80 (CR80) can be set to 00H.(3) Note on setting STOP modeBefore executing the STOP instruction, be sure to stop the timer operation (TCE80 = 0).
