W741E260 Datasheet, PDF (15/94 Pages) Winbond – 4-BIT FLASH MICROCONTROLLER

W741E260
Desired timer 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
1. MR1.3 = 1
2. MOV TM1, #I
MOV TM1, #I
MOV TM1H, R
4
MOV TM1L, R
8
Underflow
signal
4
External clock
via RC.0
Fosc/64
Fosc
MR1.0
MR1.1
FT
Auto-reload buffer
Enable
8 bits
8-bit Binary
Down Counter
(Timer 1)
Disable
Reset
Set MR1.3 to 1
MOV TM1, #I
1. MR1.3 = 0
2
circuit
Reset
MFP signal
S
Q
R
EVF.7
1. Reset
2. INT 7 accept
3. CLR EVF, #80H
4. Set MR1.3 to 1
5. MOV TM1, #I
MR1.2
MFP
output pin
Figure 7. Organization of Timer 1
For example, when FT equals 32768 Hz, depending on the preset value of TM1, the MFP 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 TM1 is shown in the table below.
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Publication Release Date: March 1998
Revision A2