Renesas H8S/2111B, Hardware Manual

Page: 267 / 582

Rev. 1.00, 05/04, page 233 of 544
11.6.5 System Reset by
RESO
Signal
Inputting the
RESO
output signal to the
RESO
pin of this LSI prevents the LSI from being
initialized correctly; the
RESO
signal must not be logically connected to the
RES
pin of the LSI.
To reset the entire system by the
RESO
signal, use the circuit as shown in figure 11.8.
RES
RESO
This LSI
Reset input
Reset signal for entire system
Figure 11.8 Sample Circuit for Resetting System by
RESO
Signal
11.6.6 Counter Values during Transitions between High-Speed, Sub-Active, and Watch
Modes
When developing a program with a program development tool (emulator), pay attention to the
followings.
When WDT_1 is used as a clock counter and is allowed to transit between high-speed mode and
sub-active or watch mode, the counter does not display the correct value due to internal clock
switching.
Specifically, when transiting from high-speed mode to sub-active or watch mode, that is, when the
control clock for WDT_1 switches from the main clock to the sub-clock, the counter incrementing
timing is delayed for approximately two to three clock cycles.
Similarly, when transiting from sub-active or watch mode to high-speed mode, the clock is not
supplied until stabilized internal oscillation is available because the main clock oscillator is halted
in sub-clock mode. The counter is therefore prevented from incrementing for the time specified by
the STS2 to STS0 bits in SBYCR after internal oscillation starts, thus producing counter value
differences for this time.
Special care must be taken when using WDT_1 as a clock counter. Note that no counter value
difference is produced while operated in the same mode.