MC68HC05F8 Datasheet, PDF (85/126 Pages) Motorola, Inc – High-density complementary metal oxide semiconductor(HCMOS) microcontroller unit

Freescale Semiconductor, Inc.
When one mode is selected, the pin associated with that mode will be activated, but the other pin
will remain at its idle state. The idle state for TONEOUT output pin is a tri-state, and TONEX output
pin is a logic high. The final state of an active pin is dependent on the values of TGER, TGEC (see
Table 9-4), FCR and FCC bits (when illegal values is input).
When both MS1 and MS0 are set, the generator can generate both single tone melody at the
column path and ToneX at the row path simultaneously.
Table 9-3 DMG Operating Modes
MS1 MS0
0
0
0
1
1
0
1
1
Mode
Sine Wave
Square Wave
ToneX
Square Wave+ToneX
TONEOUT output
DTMF / Melody
Melody
tri-state
Monotonic Melody
TONEX output
High
High
ToneX
ToneX
TGER, TGEC - Tone Generation Enable for Row and Column Paths
When both bits are held low, the DMG is disabled by forcing the two frequency counters and the
two PLA scanning counters to their reset states. The TONEOUT output is set to tri-state, the
TONEX output is set to logic low, and the active filter is turned off by shutting down all related
current sources to prevent DC power dissipation.
When a TGE bit for a path is held high (provided that the value in the frequency control register
for that path is legal, and the mode chosen is not ToneX mode) the generator is enabled. All the
counters associated with that path are then run from their reset states, and the active filter is
turned on to allow generated tone of that path to be output.
9
In DTMF dialling, the row and column tone values are first entered to the FCR and FCC registers,
and then the TGER and TGEC bits are set or reset simultaneously to achieve dual tone multiple
frequency. Similarly, in melody generation, one path is chosen as the high part, and the other, the
low part. The TGER and TGEC bits are then set and reset according to the rhythm required by the
musical tune. Of course, one can exhibits only single tone melody by disabling either TGER or
TGEC permanently. The DTMF column and row frequency tones can also be output separately
for testing by enabling just the one path.
Table 9-4 Effect of Tone Generation Enable on DMG
TGER
TGEC
Row Path Column Path
Filter
0
0
Off
Off
Off
0
1
Off
Active
Active
1
0
Active
Off
Active*
1
1
Active
Active
Active
* In ToneX mode, the filter is off and only single tone can be generated.
Tone
Silent
Single
Single
Dual*
MC68HC05F8
DTMF/MELODY GENERATOR
For More Information On This Product,
Go to: www.freescale.com
TPG
MOTOROLA
9-5