Datasheet

TIM8FR1A_000120020900 Rev. 3.00, 03/04, page 277 of 830
Section 11 16-Bit Free-Running Timer (FRT)
This LSI has an on-chip 16-bit free-running timer (FRT). The FRT operates on the basis of the 16-
bit free-running counter (FRC), and outputs two independent waveforms, and measures the input
pulse width and external clock periods.
11.1 Features
• Selection of four clock sources
 One of the three internal clocks (φ/2, φ/8, or φ/32), or an external clock input can be
selected (enabling use as an external event counter).
• Two independent comparators
 Two independent waveforms can be output.
• Four independent input capture channels
 The rising or falling edge can be selected.
 Buffer modes can be specified.
• Counter clearing
 The free-running counters can be cleared on compare-match A.
• Seven independent interrupts
 Two compare-match interrupts, four input capture interrupts, and one overflow interrupt
can be requested independently.
• Special functions provided by automatic addition function
 The contents of OCRAR and OCRAF can be added to the contents of OCRA
automatically, enabling a periodic waveform to be generated without software intervention.
The contents of ICRD can be added automatically to the contents of OCRDM × 2, enabling
input capture operations in this interval to be restricted.
Figure 11.1 shows a block diagram of the FRT.