VT82C686B
I/O Base 1 Registers – Audio FM NMI Status Registers
These registers are accessable through
I/O Base 2 Registers – MIDI / Game Port
function 5 only.
I/O Offset 1-0 – MIDI Base.............................................. RW
..................default = 0330h
15-0 MIDI Port Base Address
I/O Offset 3-2 – Game Port Base..................................... RW
.................default = 0200h
I/O Offset 0 – FM NMI Status ..........................................RO
........................................ always reads 0
7-2 Reserved
1-0 FM NMI Status
00 Undefined
15-0 Game Port Base Address
01 OPL3 Bank 0
10 OPL3 Bank 1
11 Undefined
These registers are functional only if Rx42[6] = 1
I/O Offset 1 – FM NMI Data.............................................RO
7-0 FM NMI Data
This register allows readback of the data written to
the FM data port
I/O Base 3 Registers – Codec Register Shadow
I/O Offset 2 – FM NMI Index ...........................................RO
These registers are accessable through both functions 5 and 6.
7-0 FM NMI Index
This register allows readback of the data written to
the FM index port
I/O Offset 0-7Fh – Primary Codec Shadow.................... RW
The content of these registers is updated when writing data to
primary codec registers 0-7Fh or when valid primary codec
register status is returned.
I/O Offset 80-FFh – Secondary Codec Shadow.............. RW
The content of these registers is updated when writing data to
secondary codec registers 0-7Fh or when valid secondary
codec register status is returned.
Revision 1.71 June 9, 2000
-114- Function 5 & 6 Registers - AC97 Audio & Modem Codecs
ETC [ ETC ]
