HD404618 Datasheet, PDF(63/89 Page) Hitachi Semiconductor

English

English German Russian Spanish Italian Polish Chinese Japanese Korean French Portuguese	Language :

HD404618 Datasheet, PDF (63/89 Pages) Hitachi Semiconductor – 4-Bit Single-Chip Microcomputer

◁

400 kHz (selected at TGSP reset)

800 kHz

Transformed

programmable

divider

Sine wave

counter D/A

TGSP

flag

Feedback

DTMF

HD404618 Series

TONER

VTref

Transformed

programmable

divider

Sine wave

counter D/A

TONEC

Feedback

Figure 40 DTMF Circuit Block Diagram

Tone Generator Mode Register (TGM: $010): Four-bit write-only register which controls output

frequencies (see table 30). It is cleared to $0 by MCU reset.

Table 30 Tone Generator Mode Register

TGM

Bit 3

Bit 2

Option

(TONER output

is not affected)

Bit 1

Bit 0

Option

(TONEC output is not affected)

Output Frequencies

fR1 (697 Hz)

Output through

TONER pin

fR2 (770 Hz)

fR3 (852 Hz)

fR4 (941 Hz)

fC1 (1,209 Hz)

fC2 (1,336 Hz)

fC3 (1,477 Hz)

fC4 (1,633 Hz)

Output through

TONEC pin

Tone Generator Control Register (TGC: $011): Three-bit write-only register which controls the start

and stop of DTMF signal output (see table 31). It is cleared to $0 by MCU reset.

▷