74
MC95FG308 / MC95FG208
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 mode register. To operate the watch timer, determine the input clock source, output interval and set
WTEN to ‘1’ in watch timer mode register (WTMR). It is able to execute simultaneously or individually. To stop or reset
WT, clear the WTEN bit in WTMR register. Even if CPU is STOP mode, sub clock is able to be alive so WT can
continue the operation. The watch timer counter circuits may be composed of 21-bit counter which is low 14-bit with
binary counter and high 7-bit with 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.
11.4.2 Block Diagram
Figure 11.5
Watch Timer Block Diagram
11.4.3 Register Map
Name
Address
Dir
Default
Description
WTMR
9DH
R/W
00H
Watch Timer Mode Register
WTR
9EH
W
7FH
Watch Timer Register
WTCR
9EH
R
00H
Watch Timer Counter Register
Table 11.4
Register Map
WTIF
÷
128
fx
P
r
e
s
c
a
l
e
r
MUX
WTR
÷
64
14-bit
Binary Counter
WTR Write
÷
256
f
SUB
(32.768kHz)
f
WCK
/ 2
14
Timer Counter
(7bit auto reload counter)
MUX
WTIFR
WTEN
-
-
WTIFR WTIN1 WTIN0 WTCK1 WTCK0
WTCL WTR6 WTR5 WTR4 WTR2 WTR2 WTR1 WTR0
-
WTCR6 WTCR5 WTCR4 WTCR2 WTCR2 WTCR1 WTCR0
WTCR
WTR Read
WTMR
7
f
WCK
f
WCK
/2
14
f
WCK
/2
13
f
WCK
/2
11
2
f
WCK
/ 2
14
x (7bit
WTR Value +1)
Clear
INT_ACK
Содержание MC95FG208 Series
Страница 14: ...14 MC95FG308 MC95FG208 ABOV Semiconductor Co Ltd 4 Package Diagram Figure 4 1 32 Pin SOP Package...
Страница 15: ...15 MC95FG308 MC95FG208 ABOV Semiconductor Co Ltd Figure 4 2 32 Pin QFN Package...
Страница 16: ...16 MC95FG308 MC95FG208 ABOV Semiconductor Co Ltd Figure 4 3 32 Pin LQFP Package...
Страница 17: ...17 MC95FG308 MC95FG208 ABOV Semiconductor Co Ltd Figure 4 4 28 Pin SOP Package...
Страница 18: ...18 MC95FG308 MC95FG208 ABOV Semiconductor Co Ltd Figure 4 5 28 Pin SOP Package continue...
Страница 19: ...19 MC95FG308 MC95FG208 ABOV Semiconductor Co Ltd Figure 4 6 28 Pin SOP Package...
Страница 20: ...20 MC95FG308 MC95FG208 ABOV Semiconductor Co Ltd Figure 4 7 28 Pin TSSOP Package...
Страница 21: ...21 MC95FG308 MC95FG208 ABOV Semiconductor Co Ltd Figure 4 8 20 Pin SOP Package...
Страница 22: ...22 MC95FG308 MC95FG208 ABOV Semiconductor Co Ltd Figure 4 9 20 Pin TSSOP Package...
Страница 23: ...23 MC95FG308 MC95FG208 ABOV Semiconductor Co Ltd Figure 4 10 16 Pin SOP Package...
Страница 24: ...24 MC95FG308 MC95FG208 ABOV Semiconductor Co Ltd Figure 4 11 16 Pin TSSOP Package...