AD1816 Analog Devices, AD1816 Datasheet - Page 39

• Manufacturer Part Number: AD1816
• Description: Single Chip Plug And Play Multimedia Audio Subsystem
• Manufacturer: Analog Devices

MPU-401 Registers
The AD1816A contains a set of ISA Bus registers (ports) that correspond to those used by the ISA bus MIDI audio interface cards.
Table XI lists the ISA Bus MIDI registers. These registers support commands and data transfers described in MIDI 1.0 Detailed
Specification and Standard MIDI Files 1.0, © 1994, MIDI Manufacturers Association, PO Box 3173 La Habra, CA 90632-3173.
NOTES
The AD1816A supports only the MPU-401 0xFF (reset) and 0x3F (UART) commands. The controller powers setup for Smart
mode, but must be put in pass-through mode. To start MIDI operations, send a reset command (0xFF) and then send a UART
mode command (0x3F). The MPU-401 data register contains an acknowledge byte (0xFE) after each command transfer unless it is
in UART mode..
All commands return an ACK byte in “smart” mode.
Status commands (0xAx) return ACK and a data byte; all other commands return ACK.
All commands except reset (0xFF) are ignored in UART mode. No ACK bytes are returned.
“Smart” mode data transfers are not supported.
Game Port Registers
The AD1816A contains a Game Port ISA Bus Register that is compatible with the IBM joystick standard.
REV. A
DSR (R)
DRR (R)
CMD [7:0] (W)
0x(MIDI Base+1)
STATE
NAME
BIT
Register Name
MIDI Data (r/w)
MIDI Status (r), Command (w)
Register Name
Music0: Address (w), Status (r)
Music0: Data (w)
Music1: Address (w)
Music1: Data (w)
Register Name
Game Port I/O
Data Send Ready. When read, this bit indicates that you can (0) or cannot (1) write to the
MIDI Data register. (Full = 1, Empty = 0)
Data Receive Ready. When read, this bit indicates that you can (0) or cannot (1) read from the
MIDI Data register. (Unreadable = 1, Readable = 0)
MIDI Command. Write MPU-401 commands to bits [7:0] of this register.
DRR
7
1
DSR
6
0
Table XII. Game Port ISA Bus Registers
Table XI. MPU-401 ISA Bus Registers
Table X. AdLib ISA Bus Registers
5
0
Address
(MIDI Base) Relocatable in range 0x100 to 0x3FE
(MIDI Base+1)
–39–
ISA Bus Address
(AdLib Base) Relocatable in range 0x100 – 0x3F8
(AdLib Base+1)
(AdLib Base+2)
(AdLib Base+3)
Address
(Game Port Base+0 to Game Port Base+7)
Relocatable in the range 0x100 to 0x3F8
4
0
3
0
RESERVED
2
0
1
0
AD1816A
0
0