HT95L100/10P

Rev. 0.10

18

October 1, 2002

Preliminary

Register

Label

Bits

R/W

Function

LCDIO

(28H)

¾

0~4

6~7

RO

Unused bit, read as

²0²

SPE0

5

RW

0: SEG16~ SEG19 pins are LCD segment output

1: SEG16~ SEG19 pins are PE0~PE3 pins

DTMF generator

The DTMF (Dual Tone Multiple-Frequency) signal gen-

erator is implemented in the telephone controller. It can

generate 16 dual tones and 8 single tones from the

DTMF pin. This generators also support power down,

tone on/off function. The DTMF generator clock source

is 3.58MHz, before using this function, the system oper-

ation mode must be at Normal mode.

The power down mode (D_PWDN=1) will terminate all

the DTMF generator function, however, the registers

DTMFC and DTMFD are accessible at this power down

mode.

The duration of DTMF output should be handled by the

software. DTMFD register value could be changed as

desired, the DTMF pin will output the new dual-tone si-

multaneously.

Register

Label

Bits

R/W

Function

DTMFC

(20H)

D_PWDN

0

RW

DTMF generator power down

1: DTMF generator is at power down mode.

0: DTMF generator is at operation mode.

¾

1RO

Unused bit, read as

²0²

TONE

2

RW

Tone output enable

1: DTMF signal output is enabled.

0: DTMF signal output is disabled.

¾

7~3

RO

Unused bit, read as

²0²

DTMFD

(21H)

TC4~TC1

3~0

RW

To set high group frequency

TR4~TR1

7~4

RW

To set low group frequency

The DTMF pin output is controlled by the combination of the D_PWDN, TONE, TR~TC value.

Control Register Bits

DTMF Pin Output Status

D_PWDN

TONE

TR4~TR1/TC4~TC1

1x

x

0

0

0

x

1/2 VDD

0

1

0

1/2 VDD

0

1

Any valid value

16 dual tones or 8 signal tones, bias with 1/2 VDD

1 / 2 V D D

T O N E = 1

A l l t h e t i m i n g o f t h e T O N E = 1 a n d T O N E = 0 a r e d e t e r m i n e d b y s o f t w a r e

T O N E = 0

T O N E = 1

T O N E = 0

T O N E = 1

T O N E = 0

D _ P D W N = 0

D _ P D W N = 1

DTMF output