307013-003 Datasheet, PDF (657/848 Pages) Intel Corporation – Intel I/O Controller Hub 7

AC ’97 Modem Controller Registers (D30:F3) (Desktop and Mobile Only)
17.2.1
x_BDBAR—Buffer Descriptor List Base Address Register
(Modem—D30:F3)
I/O Address:
Default Value:
Lockable:
MBAR + 00h (MIBDBAR),
MBAR + 10h (MOBDBAR)
00000000h
No
Attribute:
Size:
Power Well:
R/W
32bits
Core
Software can read the register at offset 00h by performing a single, 32-bit read from
address offset 00h. Reads across DWord boundaries are not supported.
17.2.2
Bit
31:3
2:0
Description
Buffer Descriptor List Base Address [31:3] — R/W. These bits represent address
bits 31:3. The entries should be aligned on 8-byte boundaries.
Hardwired to 0.
x_CIV—Current Index Value Register (Modem—D30:F3)
I/O Address:
Default Value:
Lockable:
MBAR + 04h (MICIV),
MBAR + 14h (MOCIV),
00h
No
Attribute:
Size:
Power Well:
RO
8bits
Core
Software can read the registers at offsets 04h, 05h and 06h simultaneously by
performing a single, 32-bit read from address offset 04h. Software can also read this
register individually by doing a single, 8-bit read to offset 04h. Reads across DWord
boundaries are not supported.
Bit
Description
7:5 Hardwired to 0.
Current Index Value [4:0] — RO. These bits represent which buffer descriptor
4:0 within the list of 16 descriptors is being processed currently. As each descriptor is
processed, this value is incremented.
17.2.3
x_LVI—Last Valid Index Register (Modem—D30:F3)
I/O Address:
Default Value:
MBAR + 05h (MILVI),
MBAR + 15h (MOLVI)
00h
Attribute:
Power Well:
R/W
Core
Software can read the registers at offsets 04h, 05h and 06h simultaneously by
performing a single, 32-bit read from address offset 04h. Software can also read this
register individually by doing a single, 8-bit read to offset 05h. Reads across DWord
boundaries are not supported.
Bit
Description
7:5 Hardwired to 0
4:0
Last Valid Index [4:0] — R/W. These bits indicate the last valid descriptor in the list.
This value is updated by the software as it prepares new buffers and adds to the list.
Intel ^® ICH7 Family Datasheet
657