Product specifications

VT8235 V-Link South Bridge
Revision 1.22 October 24, 2002 -116- Device 17 Function 6 Modem Controller Registers
Modem SGD Write Channel Registers
I/O Offset 50 – Modem SGD Write Channel Status....... RO
7 SGD Active ......................................................... RO
0 SGD has completed or been terminated default
1 SGD Active
6 SGD Paused ......................................................... RO
0 SGD not paused..................................... default
1 SGD Paused
5-4 Reserved ........................................ always reads 0
3 SGD Trigger Queued.......................................... RO
This bit reports whether the trigger used to restart the
SGD operation is queued (I/O Offset 51[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 5B-58[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 51[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 51[0] = 1.
I/O Offset 51 – Modem SGD Write Channel Control....RW
7 SGD Start ............................WO (always reads 0)
0 No effect
1 Start SGD write channel operation
6 SGD Terminate ......................WO (always reads 0)
0 No effect
1 Terminate SGD write channel operation
5-4 Test (Do Not Program) .......................always write 0
3 SGD Pause .........................................................RW
0 Release SGD write channel pause and resume
the transfer from the paused line
1 Pause SGD write channel operation (SGD
write channel pointer stays at current address)
2 Reserved ........................................ always reads 0
1 Reset Modem Write SGD Operation.................RW
0 Reserved ........................................ always reads 0
I/O Offset 52 – Modem SGD Write Channel Type........ RW
7 Auto-Start SGD at EOL
0 Stop at EOL ...........................................default
1 Auto restart at EOL
6-2 Reserved ........................................always reads 0
1 Interrupt on EOL @ End of Block
0 Disable...................................................default
1 Enable
0 Interrupt on FLAG @ End-of-Blk
0 Disable...................................................default
1 Enable
I/O Offset 57-54 – Modem SGD W Ch Table Ptr Base . RW
31-0 SGD Table Pointer Base Address (even addr)....W
Current Pointer Address .......................................R
I/O Offset 5F-5C – Modem SGD W Ch Current Count.RO
31-24 Current Modem SGD Write Channel Index
This field reports the index the SGD engine is
currently processing.
23-0 Current Modem SGD Write Channel Count
This field reports the count remaining in the current
entry being processed. For example, if 10 bytes of a
30-byte count have been transferred, this field would
read 20 to indicate 20 bytes remaining.
EOL End Of Link
. 1 indicates this block is the last of the
link. If the channel “Interrupt on EOL” bit is set,
then an interrupt is generated at the end of the
transfer.
FLAG Block Flag
. If set, transfer pauses at the end of this
block. If the channel “Interrupt on FLAG” bit is set,
then an interrupt is generated at the end of this block.
STOP Block Stop
. If set, transfer pauses at the end of this
block. To resume the transfer, write 1 to Rx?0[2].