YMU762 Datasheet, PDF (5/14 Pages) List of Unclassifed Manufacturers – Mobile Audio 3

YMU762
Outline of blocks
This section outlines functions of blocks contained in this device and flow of signals.
Register
FIFO
Instantaneous write path
FIFO
Sequencer
Delayed write path
Buffer
Instantaneous read path
Voice ROM
Headphone
Output
FM +WaveTable
Synthesizer
DAC
EQ
amp.
SRAM
Speaker
amp.
CPU interface
CPU interface is an 8-bit parallel type.
- ”Instantaneous write path” that enables Write command immediately (equipped with 64byte FIFO),
- ”Delayed write path” that enables Write command after elapse of specified time, and
- Instantaneous read path
are available.
Hardware sequencer and FIFO
The sequencer is a block that controls time and register access.
The structure of sequence data includes “time information data + MA-3 register control data”, for which 512 byte FIFO
is provided. The sequence data is written into delayed write path.
FM+Wave Table synthesizer
This device contains a Polyphonic synthesizer that adopts FM +Wave Table stereophonic hybrid system that generates
up to 40 tones.
The FM synthesizer has two operation modes; “16-Voice 4 operation mode” and “32-Voice 2 operation mode” which
can be changed to each other freely (except during tone generation).
Since waveform for FM operation can be set arbitrarily, the device is able to create voices that are more complex than
by conventional devices.
Wave Table synthesizers is able to generate eight voices simultaneously, and supports 8 bit PCM and 4 bit ADPCM
data format. The sampling frequency is 48 kHz. Stream replaying is also available, realizing interchangeability with
ADPCM replay capability of MA-2.
Voice ROM and SRAM
This device stores voice parameters (GM 128 voices + DRUM 40 voices) for FM and waveform data for Wave Table in
the ROM. SRAM is used when downloading arbitrary FM voice parameter and waveform data for Wave Table. It is
also used as waveform data buffer at stream replay with PCM/ADPCM.
DAC
Converts digital signal from a synthesizer into analog signal. The data length is 16 bit.
IRQ and TIMER
This device supports FIFO, two hardware TIMERs, and interrupt output with software interrupt.
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