Intel i7-2600 CM8062300834302S User Manual

Product codes
CM8062300834302S
Page of 296
Processor Configuration Registers
36
Datasheet, Volume 2
display initiated LP non-snoop writes (for display writing a KVM captured frame) to 
Intel ME stolen memory are allowed.
2.3.11
I/O Address Space
The system agent generates either DMI Interface or PCI Express* bus cycles for all 
processor I/O accesses that it does not claim. Configuration Address Register 
(CONFIG_ADDRESS) and the Configuration Data Register (CONFIG_DATA) are used to 
generate PCI configuration space access. 
The processor allows 64 KB+3 bytes to be addressed within the I/O space. Note that 
the upper 3 locations can be accessed only during I/O address wrap-around when 
address bit 16 is asserted. Address bit 16 is asserted on the processor bus whenever an 
I/O access is made to 4 bytes from address 0FFFDh, 0FFFEh, or 0FFFFh. Address bit 16 
is also asserted when an I/O access is made to 2 bytes from address 0FFFFh. 
A set of I/O accesses are consumed by the internal graphics device if it is enabled. The 
mechanisms for internal graphics I/O decode and the associated control is explained 
later.
The I/O accesses are forwarded normally to the DMI Interface bus unless they fall 
within the PCI Express I/O address range as defined by the mechanisms explained 
below. I/O writes are NOT posted. Memory writes to PCH or PCI Express are posted. 
The PCI Express devices have a register that can disable the routing of I/O cycles to the 
PCI Express device.
The processor responds to I/O cycles initiated on PCI Express or DMI with an UR status. 
Upstream I/O cycles and configuration cycles should never occur. If one does occur, the 
transaction will complete with an UR completion status.
Similar to FSB processors, I/O reads that lie within 8-byte boundaries but cross 4-byte 
boundaries are issued from the processor as 1 transaction. It will be broke into 2 
separate transactions. I/O writes that lie within 8-byte boundaries but cross 4-byte 
boundaries will be split into 2 transactions by the processor.
2.3.11.1
PCI Express* I/O Address Mapping
The processor can be programmed to direct non-memory (I/O) accesses to the PCI 
Express bus interface when processor initiated I/O cycle addresses are within the PCI 
Express I/O address range. This range is controlled using the I/O Base Address 
(IOBASE) and I/O Limit Address (IOLIMIT) registers in Device 1 functions 0, 1, 2 or 
Device 6 configuration space.
Address decoding for this range is based on the following concept. The top 4 bits of the 
respective I/O Base and I/O Limit registers correspond to address bits A[15:12] of an 
I/O address. For the purpose of address decoding, the device assumes that lower 12 
address bits A[11:0] of the I/O base are zero and that address bits A[11:0] of the I/O 
limit address are FFFh. This forces the I/O address range alignment to 4 KB boundary 
and produces a size granularity of 4 KB.
The processor positively decodes I/O accesses to PCI Express I/O address space as 
defined by the following equation:
I/O_Base_Address  processor I/O Cycle Address  I/O_Limit_Address