4-16
SCSI and DMA Registers
Register: 0xFC12
DMA Source/Destination Low (DSDL)
Read/Write
DSDL[7:0]
DMA Source/Destination Low
[7:0]
These register bits store the least significant byte of the
DMA function’s source address for send transfers and
destination address for receive transfers. The read value
of the DSDL and
DMA Source/Destination High (DSDH)
registers tracks the current source/destination address of
the transfer. If the transfer is interrupted for any reason,
the DSDL and DSDH registers will hold the next address
required, in case the interrupted transfer resumes.
Register: 0xFC13
DMA Source/Destination High (DSDH)
Read/Write
DSDH[7:0]
DMA Source/Destination High
[7:0]
These register bits store the most significant byte of the
DMA function’s source address for send transfers and
destination address for receive transfers. The read value
of the
DMA Source/Destination Low (DSDL)
and DSDH
registers tracks the current source/destination address of
the transfer. If the transfer is interrupted for any reason,
the DSDL and DSDH registers hold the next address
required, in case the interrupted transfer resumes.
7
6
5
4
3
2
1
0
DSDL7
DSDL6
DSDL5
DSDL4
DSDL3
DSDL2
DSDL1
DSDL0
Defaults:
0
0
0
0
0
0
0
0
7
6
5
4
3
2
1
0
DSDH7
DSDH6
DSDH5
DSDH4
DSDH3
DSDH2
DSDH0
DSDH0
Defaults:
0
0
0
0
0
0
0
0
Содержание Symbios SYM53C040
Страница 12: ...xii Preface...
Страница 90: ...4 18 SCSI and DMA Registers...
Страница 98: ...5 8 SFF 8067 Registers...
Страница 110: ...6 12 Two Wire Serial Registers...
Страница 126: ...7 16 Miscellaneous Registers...
Страница 160: ...8 34 System Registers...
Страница 184: ...9 24 Electrical Characteristics...
Страница 194: ...A 10 Register Summary...
Страница 214: ......