4552 Datasheet, PDF (36/145 Pages) Renesas Technology Corp – SINGLE-CHIP 4-BIT CMOS MICROCOMPUTER

4552 Group
• Prescaler and Timer 1 count start timing and count time when op-
eration starts
Count starts from the first rising edge of the count source (2) af-
ter Prescaler and Timer 1 operations start (1).
Time to first underflow (3) is shorter (for up to 1 period of the
count source) than time among next underflow (4) by the timing
to start the timer and count source operations after count starts.
When selecting CNTR input as the count source of Timer 1,
Timer 1 operates synchronizing with the falling edge of CNTR in-
put.
(2)
Count Source
Count Source
Selecting CNTR input
falling edge
Timer Value 3 2 1 0 3 2 1 0 3 2
Timer Underflow signal
(3)
(4)
(1) Timer Start
Fig. 24 Timer count start timing and count time when opera-
tion starts (Prescaler and Timer 1)
• Timer 2 and Timer LC count start timing and count time when op-
eration starts
Count starts from the rising edge (2) after the first falling edge of
the count source, after Timer 2 and Timer LC operations start (1).
Time to first underflow (3) is different from time among next un-
derflow (4) by the timing to start the timer and count source
operations after count starts.
(2)
Count Source
Timer Value
32 1 0 3 2 1 0 3
Timer Underflow Signal
(3)
(4)
(1) Timer Start
Fig. 25 Timer count start timing and count time when opera-
tion starts (Timer 2 and Timer LC)
Rev.3.02 Dec 22, 2006 page 36 of 142
REJ03B0023-0302