9.
The Yamaha YM2149
This is a copy from “
http://www.atari-forum.com/wiki/
“.
Software-Controlled Sound Generator (SSG)
-----------------------------------------
Overview
The SSG (Software-Controlled Sound Generator) is an NMOS-LSI device designed
to be capable of music generation. It only requires the microprocessor or
microcomputer (CPU) to initialize its register array, thus reducing the load
on the CPU. Music generation is carried out by the three sequence square wave
generator, noise generator, and envelope generator according to the set
parameters. This allows for the generation of music, special effects,
warnings, and various other types of sounds.
Features
5V single power supply
Easy connection to 8 bit or 16 bit CPU
Simple connection to external system through 2 sequence 8 bit I/O port
Wide voicing range of 8 octaves
Smooth attenuation by 5 bit envelope generator
Built-in 5 bit D/A convertor
Input of double frequency clock can be handled by built-in clock frequency
divider
TTL compatible level
Low power consumption (typical 125mW)
40 pin plastic DIL package
Pin compatible with AY-3-8910 manufactured by GI
Pin Layout
Vss(GND) 1 40 Vcc(+5V)
N.C 2 39 Test1
Analog Channel B 3 38 Analog Channel C
Analog Channel A 4 37 DA0
N.C 5 36 DA1
IOB7 6 35 DA2
IOB6 7 34 DA3
IOB5 8 33 DA4
IOB4 9 32 DA5
IOB3 10 31 DA6
IOB2 11 30 DA7
IOB1 12 29 BC1
IOB0 13 28 BC2
IOA7 14 27 BDIR
IOA6 15 26 SEL
IOA5 16 25 A8
IOA4 17 24 A9
IOA3 18 23 RESET
IOA2 19 22 CLOCK
IOA1 20 21 IOA0
Version: v005
18
Date: 22.05.2012
