Overview - Fujitsu 8FX Hardware Manual

CHAPTER 7 TIME-BASE TIMER

7.1 Overview

7.1 Overview
The time-base timer is a 24-bit free-run down-counting counter. It is
synchronized with the main clock divided by two, or with the main CR clock or
with the main CR PLL clock. The clock can be selected by the SCS[2:0] bits in
the SYCC register. The time-base timer has an interval timer function that can
repeatedly generate interrupt requests at regular intervals.
■ Interval Timer Function
The interval timer function repeatedly generates interrupt requests at regular intervals by using
the main clock divided by two, or using the main CR clock or using the main CR PLL clock as
the count clock.
• The counter of the time-base timer counts down so that an interrupt request is generated
every time a selected interval time elapses.
• The length of an interval time can be selected from the following 16 types.
Table 7.1-1 shows the interval times available for the time-base timer.
Table 7.1-1 Interval Times of Time-base Timer
Interval time if the main clock
(2
n=9
n=10
n=11
n=12
n=13
n=14
n=15
n=16
n=17
n=18
n=19
n=20
n=21
n=22
n=23
n=24
*1: F
CH
2/F
*2: F
CRH
1/F
*3: F
MCRPLL
PLL multiplication rate = 2
F
CRH
1/F
88
Interval time if the main CR
is used
n
2/F *1 )
CH
256 s
512 s
1.024 ms
2.048 ms
4.096 ms
8.192 ms
16.384 ms
32.768 ms
65.536 ms
131.072 ms
262.144 ms
524.288 ms
1.049 s
2.097 s
4.194 s
8.389 s
= 4 MHz
= 0.5 s
CH
= 4 MHz
= 0.25 s
CRH
= 8 MHz
PLL multiplication rate = 4 MHz 2 = 8 MHz
= 0.125 s
MCRPLL
FUJITSU SEMICONDUCTOR LIMITED
clock is used
n
(2 1/F *2 )
CRH
128 s
256 s
512 s
1.024 ms
2.048 ms
4.096 ms
8.192 ms
16.384 ms
32.768 ms
65.536 ms
131.072 ms
262.144 ms
524.288 ms
1.049 s
2.097 s
4.194 s
MB95630H Series
Interval time if the main CR
clock is multiplied by a PLL
multiplication rate of 2
n
(2 1/F *3 )
MCRPLL
64 s
128 s
256 s
512 s
1.024 ms
2.048 ms
4.096 ms
8.192 ms
16.384 ms
32.768 ms
65.536 ms
131.072 ms
262.144 ms
524.288 ms
1.049 s
2.097 s
MN702-00009-2v0-E