MC68HC05F8 Datasheet, PDF (86/126 Pages) Motorola, Inc – High-density complementary metal oxide semiconductor(HCMOS) microcontroller unit

Freescale Semiconductor, Inc.
Note:
The reset state of a frequency counter defines the time=0 state of a time step, whereas
the PLA scanning counters at its reset state scanning the memory location contained
the DC value of staircase sine wave.
9.4
Programming the DMG
The recommended operating procedures for the DMG are described in the below paragraphs.
Since the TONEOUT pin is an open-collector output, an external pull-up resistor of 1K to 10KΩ is
required (see Section 13 - Electrical Characteristics).
9.4.1 DTMF Dialling
To operate DTMF dialling, the sine wave mode selected. The required dual-tone (digit) are
selected through the FCR and FCC registers, and are thus output to TONEOUT pin by setting both
TGER and TGEC bits simultaneously for a period of 80ms. After generating a dual-tone, an
inter-digit delay, which is produced by tri-stating the TONEOUT output, of another 80ms before the
next dual-tone (digit) is output. This can be achieved by clearing both the TGER and TGEC bits
simultaneously, or by writing an illegal value to FCR or FCC registers.
9.4.2 Melody Generation
9
For melody generation, either sine wave or square wave mode can be selected for full
programmability. The sine wave has a flute like sound, while the square wave possesses much
richer harmonics. The required tones are selected through the FCR and FCC registers. The
selected tone is generated when the corresponding TGER or TGEC bit is set.
9.4.3 ToneX Generation
To operate ToneX generation, the ToneX mode is selected. The required tone is selected through
the FCR register. The timing of the tone can be controlled by the TGER bit.
9.4.4 Melody+ToneX Generation
To operate Melody+ToneX generation, the ToneX+Melody mode is selected. The frequencies of
the Melody tone and ToneX are selected through the FCR and FCC registers respectively,
whereas the timings of the Melody and ToneX are controlled separately by TGER and TGEC
respectively.
MOTOROLA
9-6
DTMF/MELODY GENERATOR
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TPG
MC68HC05F8