1998 May 11

8

Philips Semiconductors

Product specification

8-bit microcontroller with DTMF generator

PCD3349A

6.4

Modem frequencies

the standard modem frequency pairs summarized in

Table 5 can be implemented. It is suggested to define the

frequency by the HGF register while the LGF register

contains 00H, disabling Low Group Frequency generation.

Table 5

Standard modem frequency pairs and their

implementation

Notes

1. Standard is V.21.

2. Standard is Bell 103.

3. Standard is Bell 202.

4. Standard is V.23.

6.5

Musical scale frequencies

Finally, two octaves of musical scale in steps of semitones

can be realized, again assuming an oscillator frequency

frequency by the HGF register while the LGF contains

00H, disabling Low Group Frequency generation.

HGF

VALU

E

(HEX)

FREQUENCY (Hz)

DEVIATION

MODEM

GENERATED

(%)

(Hz)

9D

978.82

−0.12 −1.18

82

1179.03

−0.08 −0.97

8F

1073.33

0.31

3.33

79

1265.30

−0.37 −4.70

80

1197.17

−0.24 −2.83

45

2192.01

−0.36 −7.99

76

1296.94

−0.24 −3.06

48

2103.14

0.15

3.14

5C

1655.66

0.34

5.66

52

1852.77

0.15

2.77

4B

2021.20

−0.19 −3.80

44

2223.32

−0.08 −1.68

Table 6

Musical scale frequencies and their

implementation

Note

1. Standard scale based on A4 at 440 Hz.

NOTE

HGF

VALUE

(HEX)

FREQUENCY (Hz)

GENERATED

D#5

F8

622.3

622.5

E5

EA

659.3

659.5

F5

DD

698.5

697.9

F#5

D0

740.0

741.1

G5

C5

784.0

782.1

G#5

B9

830.6

832.3

A5

AF

880.0

879.3

A#5

A5

923.3

931.9

B5

9C

987.8

985.0

C6

93

1046.5

1044.5

C#6

8A

1108.7

1111.7

D6

82

1174.7

1179.0

D#6

7B

1244.5

1245.1

E6

74

1318.5

1318.9

F6

6D

1396.9

1402.1

F#6

67

1480.0

1482.2

G6

61

1568.0

1572.0

G#6

5C

1661.2

1655.7

A6

56

1760.0

1768.5

A#6

51

1864.7

1875.1

B6

4D

1975.5

1970.0

C7

48

2093.0

2103.3

C#7

44

2217.5

2223.3

D7

40

2349.3

2358.1

D#7

3D

2489.0

2470.4