REV. M

Page 19

September 1998

AS3502

14) FREQUENCY CONTROL REGISTER 3

This register contains eight bits of the 10-bit coefficient of the third frequency.

F3

D7

D6

D5

D4

D3

D2

D1

D0

Name

F37

F36

F35

F34

F33

F32

F31

F30

Default

X

X

X

X

X

X

X

X

Bit No

Symbol

Name and Description

D7-D0

F37-F30

A 10-bit coefficient (X) written into this register and into bits D0 and D1 of V3 allows to

programme the third frequency from 3.9 Hz to 3996 Hz. The coefficient in decimal

format for a given frequency can be calculated as:

X

=

f (Hz )* 256

1000

; X = (1…1023)

15) VOLUME CONTROL REGISTER 3

This register contains two bits of the third frequency coefficient and tone ringer volume mode control bits.

V3

D7

D6

D5

D4

D3

D2

D1

D0

Name

0

0

0

0

PS

PW

F39

F38

Default

X

X

X

X

X

X

X

X

Bit No

Symbol

Name and Description

D3

PS

Pulse Width Slow Bit. When set to High the pulse width step size is 4 µs. When set to

Low the pulse width step size is 1 µs.

D2

PW

Tone Ringer Volume Control Mode Bit. When set to Low pulse density volume control

is selected. When set to High pulse width volume control is selected.

D1-D0

F29-F28

These bits are the two most significant bits of the 10-bit frequency coefficient.

16) REPETITION PERIOD REGISTER

RP

D7

D6

D5

D4

D3

D2

D1

D0

Name

RP7

RP6

RP5

RP4

RP3

RP2

RP1

RP0

Default

X

X

X

X

X

X

X

X

Bit No

Symbol

Name and Description

D7-D0

RP7-RP0

An 8-bit value written into this register allows to set the repetition period with 32ms

accuracy.

X

=

Time(ms)

32ms

− 1; X= (1…255)