HD6433832S Datasheet, PDF (233/560 Pages) Renesas Technology Corp – single-chip microcomputers

Note: * Rewriting the TMIG bit may cause an internal input capture signal to be generated.
• Interval timer operation
Timer G functions as an interval timer when bit TMIG is cleared to 0 in PMR1. Following a
reset, TCG starts counting cycles of the φ/64 internal clock. This is one of four internal clock
sources that can be selected by bits CKS1 and CKS0 of TMG. TCG counts up according to the
selected clock source. When it overflows from H'FF to H'00, bit OVFL of TMG is set to 1. If
bit OVIE of TMG is currently set to 1, then bit IRRTG is set to 1 in IRR2. If bit IENTG is also
set to 1 in IENR2, then timer G requests a CPU interrupt. For further details see 3.3, Interrupts.
Count Timing: TCG is incremented by input pulses from an internal clock. TMG bits CKS1 and
CKS0 select one of four internal clocks (φ/64, φ/32, φ/2, φ_W/2) derived by dividing the system
clock (φ) or the watch clock (φ_W).
Timing of Internal Input Capture Signals:
• Timing with noise canceller function disabled
Separate internal input capture signals are generated from the rising and falling edges of the
external input signal.
Figure 9.11 shows the timing of these signals.
External input
capture signal
Internal input
capture signal F
Internal input
capture signal R
Figure 9.11 Input Capture Signal Timing (Noise Canceller Function Disabled)
• Timing with noise canceller function enabled
When input capture noise cancelling is enabled, the external input capture signal is routed via
the noise canceller circuit, so the internal signals are delayed from the input edge by five
sampling clock cycles. Figure 9.12 shows the timing.
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