HD404629R Datasheet, PDF (101/157 Pages) Renesas Technology Corp – AS Microcomputer Incorporating a DTMF Generator Circuit

TONER
VT _ref
TONEC
Sine wave
counter D/A
Feedback
Transforma-
tion program
divider
TONER output control
Sine wave
counter D/A
Feedback
Transforma-
tion program
divider
HD404629R Series
2
Tone generator
mode register
(TGM)
Tone generator
2
control register
(TGC)
TONEC output control
f _OSC
Data bus
Clock line
Signal line
400 kHz
800 kHz
1/2
2 MHz
1/5
4 MHz
1/10
400 kHz
Selector
2
System clock
selection register
(SSR)
Figure 88 Block Diagram of DTMF Circuit
99