EP80579 Datasheet, PDF (1264/1916 Pages) Intel Corporation – Intel® EP80579 Integrated Processor Product Line

Intel^® EP80579 Integrated Processor
35.7.1.2
Offset 0004h: IODATA - IODATA Register
The IODATA register exposes the internal structures within the GbE identified by the
last value written to the IOADDR register (see Section 35.7.1.1, “Offset 0000h:
IOADDR - IOADDR Register” on page 1262) to read and write accesses.
Table 35-42. Offset 0004h: IODATA - IODATA Register
Description:
View: PCI 1
BAR: IOBAR
Bus:Device:Function: M:0:0
Offset Start: 0004h
Offset End: 0007h
View: PCI 2
BAR: IOBAR
Bus:Device:Function: M:1:0
Offset Start: 0004h
Offset End: 0007h
View: PCI 3
BAR: IOBAR
Bus:Device:Function: M:2:0
Offset Start: 0004h
Offset End: 0007h
Size: 32 bit
Default: 0000000h
Power Well: Vcc
Bit Range Bit Acronym
Bit Description
31 : 00
IODATA
Data for I/O Operation: Exposes the GbE device
structure that IOADDR identifies to read and write
accesses.
Sticky
Bit Reset
Value
Bit Access
00000000h
RW
Note:
Note:
The IODATA register must always be written as a DWORD access when the IOADDR
register contains a value for the Internal Registers and Memories. In this case, writes
that are less than 32 bits will be ignored.
Reads to IODATA of any size will return a DWORD of data. However, the chipset or CPU
may only return a subset of that DWORD.
Writes and reads to IODATA when the IOADDR register value is in an undefined range
(0002_0000h -FFFF_FFFFh) should not be performed. Results are indeterministic.
There are no special software timing requirements on accesses to IOADDR or IODATA.
All accesses will be immediate except when data is not readily available or acceptable.
In this case, the GbE will delay the results through normal bus methods (e.g., split
transaction or NP Complete).
Because a register/read or write takes two IO cycles to complete, software must
provide a guarantee that the two IO cycles occur as an atomic operation. Otherwise,
results can be non-deterministic from the software viewpoint.
Intel^® EP80579 Integrated Processor Product Line Datasheet
1264
August 2009
Order Number: 320066-003US