Product specifications

VT8237R Data Sheet
Revision 2.06 December 15, 2004 -135- Device 17 Function 5 Audio Controller Registers
I/O Base 0 Regs – Audio Scatter / Gather DMA
DXS Channel 0-3 SGD Registers (x = 0-3)
I/O Offset x0 – DXS Channel x SGD Status ................RWC
7 SGD Active ..........................................................RO
0 SGD has completed or been terminated.default
1 SGD Active
6-5 Reserved ........................................ always reads 0
4 Current SGD Index Equals Stop Index .............RO
0 SGD index not equal to stop index ........default
1 SGD index being processed equals the stop
index. This bit differs from bit-2 of this
register in that this bit becomes 1 as soon as
the SGD reaches the index equal to the stop
index. Bit-2 becomes 1 after the SGD finishes
processing the index equal to the stop index.
So this bit will always turn on before bit-2.
3 SGD Trigger Queued...........................................RO
This bit reports whether the trigger used to restart the
SGD operation is queued (I/O Offset x1[1] = 1 while
the SGD engine is running).
0 SGD trigger not queued .........................default
1 SGD trigger queued (when SGD reaches EOL,
it will restart).
2 SGD Stop Interrupt Status..............................RWC
1 SGD finished the index equal to the stop index
set in xB-x8[31-24].
1 SGD EOL (End Of Link) ................................RWC
1 Block is the last of the link. May be used by
software as a signal to generate an interrupt
request if I/O Offset x1[1] = 1.
0 SGD Flag ......................................................RWC
1 Block complete. May be used by software as a
signal to generate an interrupt request if I/O
Offset x1[0] = 1.
I/O Offset x1 – DXS Channel x SGD Control ................ RW
7 SGD Start ............................WO (always reads 0)
0 No effect
1 Start SGD operation
6 SGD Terminate.......................WO (always reads 0)
0 No effect
1 Terminate SGD operation
5 SGD Auto-Start
0 Stop at EOL........................................... default
1 Auto Restart at EOL
4 Reserved ........................................always reads 0
3 SGD Pause
0 Release pause and resume the transfer
1 Pause SGD read operation (SGD pointer stays
at the current address). SGD will finish
transferring the current block before pausing.
2 Interrupt on Stop Index = Current Index and End
of Block
Controls whether an interrupt is generated when the
current index equals the stop index (x0[2] = 1).
0 Disable................................................... default
1 Enable
1 Interrupt on EOL @ End of Block
Controls whether an interrupt is generated on EOL
(x0[1] = 1).
0 Disable................................................... default
1 Enable
0 Interrupt on FLAG @ End-of-Block
Controls whether an interrupt is generated on FLAG
(x0[0] = 1).
0 Disable................................................... default
1 Enable