Rev. 1.0, 02/00, page 387 of 1141
Section 21 Prescalar Unit
21.1
Overview
The prescalar unit (PSU) has a 18-bit free running counter (FRC) that uses
φ
as a clock source and
a 5-bit counter that uses
φ
W as a clock source.
21.1.1
Features
•
Prescalar S (PSS)
Generates frequency division clocks that are input to peripheral functions.
•
Prescalar W (PSW)
When a timer A is used as a clock time base, the PSW frequency-divides subclocks and
generates input clocks.
•
Stable oscillation wait time count
During the return from the low power consumption mode excluding the sleep mode, the FRC
counts the stable oscillation wait time.
•
8-bit PWM
The lower 8 bits of the FRC is used as 8-bit PWM cycle and duty cycle generation counters.
(Conversion cycle: 256 states)
•
8-bit input capture by
,&
pins
Catches the 8 bits of 2
15
to 2
8
of the FRC according to the edge of the
,&
pin for remote control
receiving.
•
Frequency division clock output
Can output the frequency division clock for the system clock or the frequency division clock
for the subclock from the frequency division clock output pin (TMOW).