108
MC96F6432A
ABOV Semiconductor Co., Ltd.
11.4 Watch Timer
11.4.1 Overview
The watch timer has the function for RTC (Real Time Clock) operation. It is generally used for RTC design. The
internal structure of the watch timer consists of the clock source select circuit, timer counter circuit, output select circuit
and watch timer control register. To operate the watch timer, determine the input clock source, output interval and set
WTEN as
‘1’ in watch timer control register (WTCR). It is able to execute simultaneously or individually. To stop or
reset WT, clear the WTEN bit in WTCR register. Even if CPU is STOP mode, sub clock is able to be alive and so WT
can continue the operation. The watch timer counter circuits is composed of 21-bit counter. Low 14-bit is binary
counter and high 7-bit is auto reload counter in order to raise resolution. In WTR, it can control WT clear and set
Interval value at write time, and it can read 7-bit WT counter value at read time.
The watch timer supplies the clock frequency for the LCD driver (f
LCD
). Therefore, if the watch timer is disabled, the
LCD driver controller does not operate.
11.4.2 Block Diagram
P
r
e
s
c
a
l
e
r
fx
M
U
X
f
SUB
f
WCK
14Bit
Binary Counter
Timer counter
f
WCK
/2
14
WTCR
WTEN
-
-
WTIFR
WTIN1
WTIN0 WTCK1 WTCK0
MUX
f
WCK
/2
14
f
WCK
/2
13
f
WCK
/2
7
WTIFR
To interrupt
block
WTCL
WTDR6
WTDR5
WTDR4
WTDR3
WTDR2
WTDR1
WTDR0
WTDR
Write case
-
WTCNT6 WTCNT5 WTCNT4 WTCNT3 WTCNT2 WTCNT1 WTCNT0
WTCNT
Read case
Clear
INT_ACK
fx/64
fx/128
fx/256
f
LCD
=1024Hz
2
f
WCK
14
/(2 X(7 bit WTDR Value +1))
Comparator
match
Reload
Match
WTCL
Clear
Match
WTCL
Figure 11.5
Watch Timer Block Diagram
Содержание MC96F6432A
Страница 16: ...16 MC96F6432A ABOV Semiconductor Co Ltd 4 Package Diagram Figure 4 1 48 Pin QFN Package ...
Страница 17: ...17 MC96F6432A ABOV Semiconductor Co Ltd Figure 4 2 44 Pin MQFP Package ...
Страница 18: ...18 MC96F6432A ABOV Semiconductor Co Ltd Figure 4 3 32 Pin LQFP Package ...
Страница 19: ...19 MC96F6432A ABOV Semiconductor Co Ltd Figure 4 4 32 Pin SOP Package ...
Страница 20: ...20 MC96F6432A ABOV Semiconductor Co Ltd Figure 4 5 28 Pin SOP Package ...