Melody Circuit Operation - Oki ML63611 User Manual

ML63611 User's Manual
Chapter 11 Melody Driver (MELODY)
bit 1, 0: MBM1, MBM0
These bits select the buzzer output mode.
Output of two types of intermittent tones, a single tone or a continuous tone can be selected.
At system reset, MBM1 and MBM0 are cleared to "0", selecting output of intermittent tone 1.
Buzzer output mode
Intermittent tone 1
Intermittent tone 2
Continuous tone
Figure 11-2 shows the output waveforms of the melody driver output pins.
MD output
MDB output
Figure 11-2 Output Waveforms of Melody Driver Output Pins
11.4

Melody Circuit Operation

After the melody tempo is set in the tempo register (TEMP), execution of an MSA instruction will start operation
of the melody circuit.
The melody circuit outputs melody data while automatically reading melody data in ROM (program memory) as
specified by an MSA instruction. When the last melody data is read (END bit is "1"), the melody circuit
generates a melody end interrupt request. At this time, if an MSA instruction is executed, after the last melody
data is output, melody output will continue from the melody data specified by the MSA instruction. If an MSA
instruction is not executed, the melody output will stop after the last melody data is output.
MSF (bit 3 of MDCON) is a flag indicating the melody output status. When MSF is "1", the melody is being
output, and when "0", the melody is stopped. Setting MSF to "0" during melody output will forcibly stop the
melody output. If it is required to stop melody output forcibly, describe the program according to the "Note" on
page 11-3. If forcibly stopped, the melody output cannot be restarted at the address at which it was stopped.
OPTION A (C): 1.5 V (3.0 V), Without regulator
circuit for LCD bias
Single tone
Cycle specified by tone code
Output state
Waveform
Intermittent tone waveform synchronized to 8 Hz output of time
base counter
Intermittent tone waveform synchronized to the logical AND of
8 Hz signal output and a "L" level of 1 Hz signal output of the
time base counter
Single tone waveform beginning when EMBD is set to "1" until
second falling edge of 32 Hz output of time base counter
Continuous tone waveform that is constant while EMBD is "1"
No output state
11 – 4
OPTION B (D): 1.5 V (3.0 V), With regulator
Output state
circuit for LCD bias