82C931 Datasheet, PDF (38/64 Pages) List of Unclassifed Manufacturers – Plug and Play Integrated Audio Controller

82C931
(3) To access MCIR1-23, write the corresponding register
index into the address access port and read (or write) the
data from (or to) the data access port. This read or write
is only possible if the correct password (E4h) has been
written into Port 0F8Dh, or is disabled (0F8Dh[7] = 1).
Tables 5-3 through 5-5 illustrate the necessary steps to
access MCIR1-23. Table 5-6 gives the bit formats for the
MCIR1-23.
Table 5-3 MCBase, Direct MC Register
7
6
5
4
3
2
1
0
Port 0F8Dh
Pass word pro-
tection for
access to
address or data
port:
0 = Enable
1 = Disable
Reserved
MCBase Register (WO)
These bits specify the address for
MCIdx[8:4] and MCData[8:4]: (Refer to Table 5-4.)
Address range = 00000 through 11111
Table 5-4 McBase, Index (MCIndx) and Data (MCData) Ports Address Range
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Index Port Address [15:0]
0
0
0
0
1
1
1
Specified by MCBase[4:0]
(Refer to Table 5-3)
1
1
1
0
Data Port Address [15:0]
0
0
0
0
1
1
1
Specified by MCBase[4:0]
(Refer to Table 5-3)
1
1
1
1
Table 5-5
7
0
MCIdx and MCData Registers
6
5
4
3
2
1
0
MCIdx
0
0
Specifies which MCIR register is to be accessed.
00000 = Disable
01101 = MCIR13: PNP Status
00001 = MCIR1:Base/Type Configuration
00010 = MCIR2: Reserved
00011 = MCIR3: SB/WSS Configuration
01110 = MCIR14: PNP CSN
01111 = MCIR15: PNP READ_DATA
10000 = MCIR16: Volume Control
00100 = MCIR4: User Programmable GP
00101 = MCIR5: Option
10001 = MCIR17: Serial EEPROM
10010 = MCIR18: CONFIG Status
00110 = MCIR6: MIDI Interface
00111 = MCIR7: Semaphore Software
01000 = MCIR8: Reserved
10011 = MCIR19: FM Control
10100 = MCIR20: GPIO Control
10101 = MCIR21: Serial Audio Control
01001 = MCIR9: Test Control
01010 = MCIR10: Test Control
01011 = MCIR11: Status
01100 = MCIR12: Test
10110 = MCIR22: Serial Audio Control
10111 = MCIR23: Reserved
Remaining combinations = Reserved
MCData (refer to Table 5-6)
OPTi
®
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Revision: 2.1