W741C260 Datasheet, PDF (12/92 Pages) Winbond – 4-BIT MICROCONTROLLER

W741C260
Fosc/1024
Fosc/4
1. Reset
2. CLR EVF, #02H
3. Reset MR0.3 to 0
4. MOV TM0L, R or MOV TM0H, R
MR0.0
Disable
Enable
1. Set MR0.3 to 1
2. MOV TM0, #I
8-bit Binary
Down Counter
(Timer 0)
4
4
8
S
Q
R _EVF.1
MOV TM0H, R MOV TM0L, R
MOV TM0, #I
HEF.1
IEF.1
Hold mode release (HCF.1)
Timer 0 interrupt (INT1)
1. Reset
2. CLR EVF, #02H
3. Set MR0.3 to 1
4. MOV TM0, #I
Figure 5. Organization of Timer 0
2. Timer 1 (TM1)
Timer 1 (TM1) is also a programmable 8-bit binary down counter, as shown in Figure 6. Timer 1 can
be used as a counter to count external events or to output an arbitrary frequency to the MFP pin. The
input clock of Timer 1 can be one of three sources: FOSC/64, FOSC, or an external clock from the
RC.0 input pin. The source can be selected by setting bit 0 and bit 1 of mode register 1 (MR1). At
initial reset, the Timer 1 clock input is FOSC. If an external clock is selected as the clock source of
Timer 1, the content of Timer 1 is decreased by 1 at the falling edge of RC.0. When the MOV TM1L,
R or MOV TM1H, R instruction is executed, the specified data are loaded into the auto-reload buffer
and the TM1 down-counting will be disabled (i.e. MR1.3 is reset to 0). If the bit 3 of MR1 is set
(MR1.3 = 1), the contents of the auto-reload buffer will be loaded into the TM1 down counter, Timer 1
starts to down count, and the event flag 7 is reset (EVF.7 = 0). When the MOV TM1, #I instruction is
executed, the event flag 7 (EVF.7) and MR1.3 are reset and the specified value is loaded into auto-
reload buffer and TM1 by the internal hardware, then the MR1.3 is set, that is the TM1 starts to count
by the hardware. When the timer decrements to FFH, it will generate an underflow (EVF.7 = 1) and
be auto-reloaded with the specified data, after which it will continue to count down. An interrupt is
executed if the interrupt enable flag 7 has been set to 1 (IEF.7 = 1), and the hold state is terminated if
the hold mode release enable flag 7 is set to 1 (HEF.7 = 1). The specified frequency of Timer 1 can
be delivered to the MFP output pin by programming bit 2 of MR1. Bit 3 of MR1 can be used to make
Timer 1 stop or start counting.
If the Timer 1 clock input is FT, then:
Desired Timer 1 interval = (preset value +1) / FT
Desired frequency for MFP output pin = FT ÷ (preset value + 1) ÷ 2 (Hz)
Preset value: Decimal number of Timer 1 preset value, and
FOSC: Clock oscillation frequency
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