VT82C686B
Read / Write through function 5, R/O through function 6.
The following set of registers is dedicated for FM:
I/O Offset 20 – FM SGD Read Channel Status ...........RWC
7
6
SGD Active (0 = completed or terminated)........RO
SGD Paused..........................................................RO
........................................ always reads 0
5-4 Reserved
3
2
1
0
SGD Trigger Queued (will restart after EOL) ..RO
SGD Stopped (write 1 to resume) ...................RWC
SGD EOL ......................................................RWC
SGD Flag ......................................................RWC
I/O Offset 21 – FM SGD Read Channel Control............RW
7
6
SGD Start ............................WO (always reads 0)
0
No effect
1
Start SGD read channel operation
SGD Terminate ......................WO (always reads 0)
0
No effect
1
Terminate SGD read channel operation
.....always reads 0, writing 1 not allowed
5-4 Reserved
3
SGD Pause .........................................................RW
0
1
Release SGD read channel pause and resume
the transfer from the paused line
Pause SGD read channel operation (SGD read
channel pointer stays at the current address)
........................................ always reads 0
2-0 Reserved
I/O Offset 22 – FM SGD Read Channel Type ................RW
(1=Enable) ....... default = 0
Auto-Start SGD at EOL
7
........................................ always reads 0
6-4 Reserved
3-2 Interrupt Select
00 Interrupt at PCI Read of Last Line .........default
01 Interrupt at Last Sample Sent
10 Interrupt at Less Than One Line to Send
11 -reserved-
1
0
Interrupt on EOL @ End of Block
0
Disable ...................................................default
1
Enable
Interrupt on FLAG @ End-of-Blk
0
Disable ...................................................default
1
Enable
I/O Offset 27-24 – FM SGD Rd Ch Table Pointer Base RW
31-0 SGD Table Pointer Base Address (even addr).....W
Current Pointer Address........................................R
I/O Offset 2F-2C – FM SGD Rd Chan Current Count...RO
........................................ always reads 0
31-24 Reserved
23-0 Current SGD FM Read Channel Count
Revision 1.71 June 9, 2000
-111- Function 5 & 6 Registers - AC97 Audio & Modem Codecs
ETC [ ETC ]
