W742E816 データシートの表示（PDF） - Winbond

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コンポーネント説明

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W742E816

4-BIT MICROCONTROLLER

Winbond 

W742E/C816

Deleted: SA5505

Deleted: W742C811

5.12.2 Timer 1 (TM1)

Timer 1 (TM1) is also a programmable 8-bit binary down counter, as shown in Figure 5-7. Timer 1 can

output an arbitrary frequency to the MFP pin. The input clock of Timer 1 can be one of three sources:

FOSC/64, FOSC or FS. 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. 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 that is MR1.3 is reset to 0 at the same time. If the bit 3 of MR1 is set (MR1.3 = 1), the

content of the auto-reload buffer will be loaded into the TM1 down counter, and Timer 1 starts to down

count, and the event flag 7 is reset (EVF.7 = 0). When the timer decrements to 0FFH, it will generate

an underflow (EVF.7 = 1) and be auto-reloaded with the specified data, after which it will continue to

count down. Then, if interrupt enable flag 7 has been set to 1 (IEF.7 = 1), an interrupt is executed; if

hold mode release enable flag 7 is set to 1 (HEF.7 = 1), the hold state is terminated. 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.

In a case where Timer 1 clock input is FT:

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

FOSC: Clock oscillation frequency

Fs

Fosc/64

Fosc

MR1.0

MOV TM1H, R

MOV TM1L, R

4

4

MR1.3

MR1.1

Auto-reload Buffer

Enable

8 bits

FT

8-Bit Binary

Down Counter

(Timer 1)

Disable

Reset

Set MR1.3 to 1

S

Q

R

Underflow signal

EVF.7

1. Reset

2. INT7 accept

3. CLR EVF, #80H

4. Set MR1.3 to 1

2

Circuit

Reset

MFP signal

MR1.2

MFP

output pin

MOV TM1L, R or MOV TM1H, R

Figure 5-7. Organization of Timer 1

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