W925E240 Datasheet, PDF (43/73 Pages) Winbond – 8-BIT CID MICROCONTROLLER

W925E/C240
Table 5 The relation between the tone frequency and the preset value of TM0
3rd octave
Tone
frequency
C
130.81
C ^# 138.59
D
146.83
T _{D # 155.56}
O^E
F
164.81
174.61
N ^{F # 185.00}
G
196.00
E _G # _207.65
A
220.00
A ^# 233.08
B
246.94
TM0 preset value
& BUZ frequency
83H 131.07
8AH 138.84
90H 146.28
97H 156.03
9DH 165.49
A2H 174.30
A7H 184.09
ACH 195.04
B1H 207.39
B6H 221.40
BAH 234.05
BEH 248.24
4th octave
Tone
frequency
TM0 preset value
& BUZ frequency
261.63
C1H 260.06
277.18
C5H 277.69
293.66
C8H 292.57
311.13
CBH 309.13
329.63
CEH 327.68
349.23
D1H 348.58
369.99
D4H 372.35
392.00
D6H 390.08
415.30
D9H 420.10
440.00
DBH 442.81
466.16
DDH 468.11
493.88
DF
496.48
H
5th octave
Tone
frequency
TM0 preset value
& BUZ frequency
523.25
E1H 528.51
554.37
E3H 564.96
587.33
E4H 585.14
622.25
E6H 630.15
659.26
E7H 655.36
698.46
E9H 712.34
739.99
EAH 744.72
783.99
EBH 780.19
830.61
ECH 819.20
880.00
EDH 862.84
932.23
EEH 910.22
987.77
EFH 963.76
Note: Central tone is DB (440 Hz).
WATCHDOG TIMER
The Watchdog timer is a free-running timer that can be programmed by the user to serve as a system
monitor, a time-base generator or an event timer. It is a set of dividers that divides the system clock.
The divider output is selectable and determines the time-out interval. In the condition of the timer-out
expiring, the WDT interrupt and WDT reset may be executed if the corresponding enables control bits
are set. The interrupt will occur if the individual interrupt enable and the global enable are set. The
interrupt and reset functions are independent of each other and may be used separately or together
depending on the users software.
Fsub
Fosc
1
WFS(WDCON.4)
Reset Watchdog
RWT (WDCON.0)
12
13 15
16 18
19 21
WD1,WD0
00
01
10 ^Time-out
11
selector
WDIF
EWDI(EIE.5)
WTRF
512 clock
delay
Enable Watchdog timer reset
EWT(WDCON.1)
Interrupt
Reset
Figure 6-7 Watchdog Timer
- 43 -
Publication Release Date: July 12, 2005
Revision A10