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Preliminary W742C(E)811
Publication Release Date: May 1999
- 27 -
Revision A1
Auto-reload buffer
8 bits
MR1.3
Underflow signal
EVF.7
1. Reset
2. INT7 accept
3. CLR EVF, #80H
4. Set MR1.3 to 1
MFP
MFP signal
MR1.2
output pin
8-Bit Binary
Down Counter
(Timer 1)
2
circuit
Reset
Reset
Disable
Enable
Fosc/64
Fosc
MR1.0
S
R
Q
T
F
MOV TM1L,R or MOV TM1H,R
4
4
MOV TM1H,R
MOV TM1L,R
Set MR1.3 to 1
MR1.1
Fs
Figure 5-7 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.
Table 2 The relation between the tone frequency and the preset value of TM1
C
C
#
D
D
#
B
G
G
A
F
F
E
A
#
#
#
E
N
O
T
TM1 preset value
& MFP frequency
3rd octave
4th octave
5th octave
261.63
277.18
293.66
311.13
329.63
349.23
369.99
392.00
415.30
440.00
466.16
493.88
523.25
554.37
587.33
622.25
659.26
698.46
739.99
783.99
830.61
880.00
932.23
987.77
260.06
277.69
292.57
309.13
327.68
372.36
390.09
420.10
443.81
442.81
3EH
3AH
37H
34H
31H
2EH
2BH
29H
26H
22H
24H
20H
468.11
496.48
1EH
1CH
1BH
19H
18H
16H
15H
14H
13H
12H
11H
10H
528.51
564.96
585.14
630.15
655.36
712.34
744.72
780.19
819.20
862.84
910.22
963.76
130.81
138.59
146.83
155.56
164.81
174.61
185.00
196.00
207.65
220.00
233.08
246.94
7CH
75H
6FH
68H
62H
5DH
58H
53H
4EH
45H
49H
41H
131.07
138.84
146.28
156.03
165.49
174.30
184.09
195.04
207.39
221.40
234.05
248.24
Tone
frequency
Tone
frequency
TM1 preset value
& MFP frequency
Tone
frequency
TM1 preset value
& MFP frequency
Note: Central tone is A4 (440 Hz).