9.3
Operation
9.3.1
TCNT Increment Timing
The timer counter increments on a pulse generated once for each period of the selected (internal or
external) clock source.
Internal Clock: Internal clock sources are created from the system clock by a prescaler. The
counter increments on an internal TCNT clock pulse generated from the falling edge of the
prescaler output, as shown in figure 9.2. Bits CKS2 to CKS0 of TCR and bits ICKS1 and ICKS0
of STCR can select one of the six internal clocks.
ø
Internal
clock
TCNT clock
pulse
TCNT
N – 1
N
N + 1
Figure 9.2 Increment Timing for Internal Clock Input
201
RENESAS [ RENESAS TECHNOLOGY CORP ]
