YMF721
OPL4-ML2
FM + Wavetable Synthesizer LSI
YAMAHA CORPORATION
July 10, 1997
YMF721 CATALOG
CATALOG No.:LSI-4MF721A20
Jury 10, 1997
OVERVIEW
YMF721 (OPL4-ML2) is a high quality and low cost Wavetable synthesizer LSI. YMF721 (OPL4-ML2)
integrates an OPL3 (FM synthesizer), General MIDI processor and 1 Mbyte Wavetable sample ROM into one
chip, and complies with General MIDI (GM) system level 1. Thus, it is best suited to multimedia applications,
sound cards, MIDI synthesis modules and other sound applications.
Since this LSI outputs stereophonic 16 bit digital signal (fs = 44.1 kHz), it can be connected directly with
YMF701B, 711 or 715 (OPL3-SA, SA2 or SA3) or with YAC516(DAC16-L).
Operating voltage, 3.3 V, allows this LSI to be controlled with notebook personal computers.
Power management functions (power down and suspend/resume functions) of OPL4-ML2 contribute to low
power consumption of personal computers into which this product is built-in.
FEATURES
The Wavetable synthesizer of this LSI is able to generate up to 24 types of sounds simultaneously.
Has an interface that makes this LSI compatible with MPU-401 UART mode.
Has an OPL3 (FM synthesizer) for AdLib/Sound Blaster applications.
Has a 1 Mbyte built-in Wavetable sample ROM.
Complies with GM system Level 1. (Thus, it is compatible with DOS applications that support MPU-401.)
MIDI signal can be transmitted either through serial input or parallel input.
FM synthesizer and Wavetable synthesizer of this LSI can generate their sound at the same time.
FM synthesizer is register-compatible with OPL3.
All registers are readable.
Power management functions included power down and suspend/resume can be supported.
Frequency of master clock signal is 33.8688 MHz.
Pin compatible with YMF704C-S (100 pin SQPF)
Voltage of power supply can be 5.0 V or 3.3 V.
Silicone gate CMOS process
100-pin SQFP (YMF721-S).
GENERAL MIDI logo is a trademark of Association of Musical Electronics Industry (AMEI), and
indicates GM system level 1 Compliant.
YMF721
July 10, 1997
- 3 -
PIN DESCRIPTION
ISA bus interface : 19 pins
Pin name
pins
I/O
Type
Size
Function
ADB7-0
8
I/O
TTL
2mA
Data bus
A2-0
3
I
TTL
-
Address bus
/MPUCS
1
I
TTL
-
MPU401 chip select
/OPLCS
1
I
TTL
-
FM/Wavetable/Command/Control chip select
/IOW
1
I
TTL
-
Write enable
/IOR
1
I
TTL
-
Read enable
RST
1
I
TTL
-
Initial clear input
AIRQ
1
O
TTL
2mA
Interrupt signal ("H" : Interrupt)
ABDIR
1
O
TTL
2mA
Selection of data transfer direction
("L" : YMF721
Host)
ARDY
1
OD
TTL
12mA
I/O channel ready/busy selection ("L" : Busy)
MIDI interface : 2 pins
Pin name
pins
I/O
Type
Size
Function
RXD
1
I
TTL
-
MIDI serial data input
FSP
1
I
TTL
-
Selection of MIDI serial/parallel transmission
("H" : Parallel, "L" : Serial)
Serial audio interface : 8 pins
Pin name
pins
I/O
Type
Size
Function
CLKO
1
O
CMOS
8mA
Clock output (384fs = 16.9344MHz)
BCO
1
O
CMOS
2mA
Bit clock output (48fs = 2.1168MHz)
LRO
1
O
CMOS
2mA
L/R clock output (fs = 44.1kHz)
WCO
1
O
CMOS
2mA
Word clock output (2fs = 88.2kHz)
DO3
1
O
CMOS
2mA
Effect send output
DO2
1
O
CMOS
2mA
MIX (FM + Wavetable) output
DO1
1
O
CMOS
2mA
Wavetable output
DO0
1
O
CMOS
2mA
FM output
YMF721
July 10, 1997
- 4 -
Others : 39 pins
Pin name
pins
I/O
Type
Size
Function
5V/3V
1
I
CMOS
-
Selection of power supply
/RESETSEL
1
I+
TTL
-
RST signal polarity control pin
(When this pin is at "L", RST is active at "L".)
/PDOUT
1
O
CMOS
2mA
Power down control output
XI
1
I
CMOS
2mA
Crystal oscillator connection or master clock input
(33.8688 MHz)
XO
1
O
CMOS
2mA
Crystal oscillator connection pin
N.C.
34
-
-
-
To be open at normal use.
LSI test pins : 21 pins
Pin name
pins
I/O
Type
Size
Function
/TESTA
1
I+
TTL
-
To be open at normal use.
/TESTB
1
I+
TTL
-
To be open at normal use.
/TEST
1
I+
TTL
-
To be open at normal use.
/TEST2
1
I+
TTL
-
To be open at normal use.
/TEST3
1
I+
TTL
-
To be open at normal use.
T7-0
8
O
CMOS
2mA
To be open at normal use.
TD7-0
8
I/O
CMOS
2mA
To be open at normal use.
Power supply, ground : 11 pins
Pin name
pins
I/O
Type
Size
Function
VDD
4
-
-
-
Power supply (put on +5.0 V or +3.3V)
VSS
7
-
-
-
Ground
Total : 100 pins
Note : I+ : Input pin with built-in pull-up resistor, OD : Open drain output pin
PDF 
ZIP
