4513_03 Datasheet, PDF (142/210 Pages) Renesas Technology Corp – 4-BIT SINGLE-CHIP MICROCOMPUTER

APPLICATION
2.3 Timers
2.3.4 Notes on use
(1) Prescaler
Stop the prescaler operation to change its frequency dividing ratio.
(2) Count source
Stop timer 1, 2, 3, or 4 counting to change its count source.
(3) Reading the count values
Stop timer 1, 2, 3, or 4 counting and then execute the TAB1, TAB2, TAB3, or TAB4 instruction to
read its data.
(4) Writing to reload registers R1, R3
When writing data to reload registers R1, R3 while timer 1 and 3 are operating, avoid a timing when
timers 1 and 3 underflow.
4513/4514 Group User’s Manual
2-39