EM78815
8-Bit Microcontroller
7.2.16.4 Page 3 Tone 1 Control Register
Bit 7
T17
Bit 6
T16
Bit 5
T15
Bit 4
T14
Bit 3
T13
Bit 2
T12
Bit 1
T11
Bit 0
T10
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
Bit 0~Bit 7 (T10~T17) : Tone Generator 1 frequency divider and power control. Run
in Normal mode.
Clock source = 85300Hz
T17~T10 = ‘11111111’ → Tone Generator 1 will has 334 (85300/255) Hz Sine wave
output.
:
T17~T10 = ‘00000010’ → Tone Generator 1 will has 41150(85300/2) Hz Sine wave
output.
T17~T10 = ‘00000001’ → DC bias voltage output
T17~T10 = ‘00000000’ → Power off
Built-in tone generator can generate dialing tone signals for dialing tone type
telephones or just a single tone. In DTMF application, there are two kinds of tones,
One is the row frequency group (Tone 1), the other is the column frequency group
(Tone 2). Each group has four kinds of frequency, user can get a total of 16 kinds of
DTMF frequency. A Tone generator contains a row frequency sine wave generator
for generating the DTMF signal which is selected by RA Page 3 and a column
frequency sine wave generator for generating the DTMF signal which is selected by
RB Page 3. This block can generate a single tone by filling one of these two
registers.
If all the values are low, the power of the tone generators will be turned off.
Tone 2 (RB Page 3) High Group Freq.
1201.4Hz 1332.8Hz 1470.7Hz 1640.4Hz
(0X47)
(0X40)
(0X3A)
(0X34)
Tone 1 (RA page3)
Low group freq.
699.2Hz (0x07A)
768.5Hz (0x06F)
853.0Hz (0x064)
937.4Hz (0x05B)
1
4
7
*
2
5
8
0
3
6
9
#
A
B
C
D
Tone 1 and Tone 2 are asynchronous tone generators and both can be used to
generate Caller ID FSK signal. In FSK generator application, Tone 1 or Tone 2 can
generate 1200Hz Mark bit and 2200Hz Space bit for Bell202 or 1300Hz Mark bit and
2100Hz Space bit for V.23. See the following table.
Product Specification (V2.4) 08.01.2004
(This specification is subject to change without further notice)
39
ELAN [ ELAN MICROELECTRONICS CORP ]
