W925E240 Datasheet, PDF (42/73 Pages) Winbond – 8-BIT CID MICROCONTROLLER

W925E/C240
MODE 2
Mode 2 is the Auto Reload Mode. In mode 2, TLx acts as an 8-bit count register, while THx holds the
reload value. When the TLx register overflows from FFh to 00h, the TFx bit is set and TLx is reloaded
with the content of THx, and the counting process continues from the reloaded TLx. The reload
operation leaves the content of the THx register unchanged. Counting is controlled by the TRx bit and
the proper setting of GATE and INTx pins.
BUZZER
In mode 2, timer 0 can be use to output an arbitrary frequency to the BUZ pin by programming bit6
and bit7 of CKCON2. BUZ pin can be configured as key tone (KT) output by setting BUZSL to high.
When disable buzzer output by clearing ENBUZ to low, the BUZ output is in floating status.
In the case where timer 0 clock input is FT, the desired frequency for BUZ output = FT / (255 – preset
value + 1) / 2 (HZ).
CKCON2.5, CKCON2.4
Low
TM0=CKCON1.2, CKCON1.3
(TM1=CKCON1.4, CKCON1.5)
512Hz
1024Hz
Fosc/4 ⁰⁰
Fosc/64 ⁰¹
Fosc/1024 ^{10 mux}
Fs ¹¹
T0 = P3.4
2048Hz
C/T = TMOD.2
(C/T = TMOD.6)
0 _FT
1
0
(T1 = P3.5)
TR0 = TCON.4
(TR1 = TCON.6)
00
01
10 mux
11
TL0
From
TM0
(TL1)
CKCON2.6 CKCON2.7
=BUZSL =ENBUZ
KT
1/2
Pin BUZ
floating
7
TFx
Interrupt
TF0
(TF1)
GATE = TMOD.3
(GATE = TMOD.7)
INT0 = P3.2
(INT1 = P3.3)
0
7
TH0
(TH1)
PS: Functions of timer1 are shown in brackets
Figure 6-6 Mode 2 of Timer/Counter 0 & 1
When FT equals 32768 Hz, depending on the preset value of TM0, the BUZ pin will output a single
tone signal in the tone frequency range from 64 Hz to 16384 Hz. The relation between the tone
frequency and the preset value of TM0 is shown in the table below.
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