User guide

65
SmartBook for Renesas R8C/Tiny Microcontrollers
www.MightyMicons.com
7.2 Timer Mode:
Most of the timers of the R8C/Tiny have this mode. This helps the designers
generate different time delays or generate the interrupts at the regular intervals.
The 8-bit timers are formed using an 8 bit timing mechanism along with an 8 bit
prescalar. These timers have an 8 bit prescalar cascaded with the timing register.
Every underflow of this prescalar decrements a count in the 8 bit timing register.
These two 8 bit registers are supported with two other 8 bit reloading registers.
When the timers are configured or set with the data during the initialization, these
reloading registers also get the same data and retain them till the next setting.
When these 8 bit registers, prescalar and the timing registers underflow, the re-
load registers automatically load these registers with their con-
tents.
Most of the time, these timers operate as down
counters using internally generated clock signals.
Facility is available to select the required clock
signal from few options through the clock divid-
ers. Timers start their operation by setting a
start bit in the specified register. Then the se-
lected clock signal starts counting the
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Timer mode
helps the designers
generate different time de-
lays or
generate the
interrupts at
the regular in-
tervals.