SH7750_08 Datasheet, PDF (437/1162 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer

Section 12 Timer Unit (TMU)
• Operating on external clock
For channels 0 to 2, external clock pin (TCLK) input can be selected as the timer clock by
means of the TPSC2–TPSC0 bits in TCR. The rising edge, falling edge, or both edges can be
selected as the detected edge of the external clock with the CKEG1 and CKEG0 bits in TCR.
Figure 12.5 shows the timing for both-edge detection.
Pck
External clock
input pin
TCNT
N+1
N
N–1
Figure 12.5 Count Timing when Operating on External Clock
• Operating on on-chip RTC output clock
The on-chip RTC output clock can be selected as the timer clock in channels 0 to 2 by means
of the TPSC2–TPSC0 bits in TCR. Figure 12.6 shows the timing in this case.
RTC output clock
TCNT N + 1
N
N–1
Figure 12.6 Count Timing when Operating on On-Chip RTC Output Clock
12.3.2 Input Capture Function
Channel 2 has an input capture function.
The procedure for using the input capture function is as follows:
1. Use the TCOE bit in the timer output control register (TOCR) to set the TCLK pin to input
mode.
2. Use bits TPSC2–TPSC0 in the timer control register (TCR) to set an internal clock or the on-
chip RTC output clock as the timer operating clock.
Rev.7.00 Oct. 10, 2008 Page 353 of 1074
REJ09B0366-0700