YMU757B Datasheet, PDF (3/43 Pages) YAMAHA CORPORATION – MA-1C

YMU757B
General description of YMU757B
The YMU757B is controlled by way of the serial interface.
Shown below is its internal configuration.
SDIN
SYNC
SCLK
/IRQ
Serial
interface
Musical score
data
Volume, power management, etc.
Timbre Data
Tempo
START/STOP
Timbre allotment
Timbre
register
FIFO
32word
Sequencer
FM
Synthesizer
D/A +
Volume
AMP
HPOUT
SPOUT
When the data is inputted into the serial interface, it is converted into the parallel data and transmitted to each
function block according to the index address.
The musical score data is stored in the 32-word FIFO first and then transmitted to the sequencer where it is interpreted
and signals to control sound generation of the FM synthesizer is output.
The timbre register is where up to 8 timber data can be stored.
Also, as the sequencer controlling parameters, the start/stop and tempo signals are provided.
In order to have sound generated, the following processes must be performed for this LSI.
1) Initial status setting (cancellation of power-down function, clock selection, etc.)
2) Timbre data setting
3) Writing the musical score data in FIFO before starting the sequence
4) Writing the next musical score data before FIFO becomes empty upon receipt of the interrupt signal from
FIFO during reproduction,.
(For the details, refer to "Settings & procedure required to generate melody".)
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