
Preliminary W741C20X
Publication Release Date: March 1998
- 13 -
Revision A3
For example, when F
T
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.
3rd octave
4th octave
5th octave
Tone
frequency
TM1 preset value &
MFP frequency
Tone
frequency
TM1 preset value &
MFP frequency
Tone
frequency
TM1 preset value &
MFP frequency
C
130.81
7CH
131.07
261.63
3EH
260.06
523.25
1EH
528.51
C#
138.59
75H
138.84
277.18
3AH
277.69
554.37
1CH
564.96
T
D
146.83
6FH
146.28
293.66
37H
292.57
587.33
1BH
585.14
D#
155.56
68H
156.03
311.13
34H
309.13
622.25
19H
630.15
O
E
164.81
62H
165.49
329.63
31H
327.68
659.26
18H
655.36
F
174.61
5DH
174.30
349.23
2EH
372.36
698.46
16H
712.34
N
F#
185.00
58H
184.09
369.99
2BH
390.09
739.99
15H
744.72
G
196.00
53H
195.04
392.00
29H
420.10
783.99
14H
780.19
E
G#
207.65
4EH
207.39
415.30
26H
443.81
830.61
13H
819.20
A
220.00
49H
221.40
440.00
24H
442.81
880.00
12H
862.84
A#
233.08
45H
234.05
466.16
22H
468.11
932.23
11H
910.22
B
246.94
41H
248.24
493.88
20H
496.48
987.77
10H
963.76
Note: Central tone is A4 (440 Hz).
Mode Register 0 (MR0)
Mode Register 0 is organized as a 4-bit binary register (MR0.0 to MR0.3). MR0 can be used to control
the operation of Timer 0. The bit descriptions are as follows:
W
W
0
1
2
3
MR0
Note: W means write only.
Bit 0 = 0 The fundamental frequency of Timer 0 is F
OSC
/4.
= 1 The fundamental frequency of Timer 0 is F
OSC
/1024.
Bit 1 & Bit 2 are reserved
Bit 3 = 0 Timer 0 stops down-counting.
= 1 Timer 0 starts down-counting.