h8s-2138 Renesas Electronics Corporation., h8s-2138 Datasheet - Page 416

• Manufacturer Part Number: h8s-2138
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

Section 13 Timer Connection [H8S/2138 Group]
13.3.5
IVI Signal Fall Modification and IHI Synchronization
By using the timer connection TMR1, the fall of the IVI signal can be shifted backward by the
specified number of IHI signal waveforms. Also, the fall of the IVI signal can be synchronized
with the rise of the IHI signal.
To perform 8-bit timer divided waveform period measurement, TCNT in TMR1 is set to count
external clock (IHI signal) pulses, and to be cleared on the rising edge of the external reset signal
(inverse of the IVI signal). The number of IHI signal pulses until the fall of the IVI signal is
written in TCORB.
Since the IVI signal supplied to the IVO signal selection circuit is normally set on the rise of the
IVI signal and reset on the fall, its waveform is the same as that of the original IVI signal. When
fall modification is selected, a reset is performed on a TMR1 TCORB compare-match.
The fall of the waveform generated in this way can be synchronized with the rise of the IHI signal,
regardless of whether or not fall modification is selected.
Examples of TMR1 TCORB, TCR, and TCSR settings are shown in table 13.7, and the fall
modification/IHI synchronization timing chart is shown in figure 13.7.
Rev. 4.00 Jun 06, 2006 page 362 of 1004
REJ09B0301-0400