Avago Technologies LSI53C876E - Manual (Page 28)

2-6 Functional Description
2.1.2.6 Memory Read Command
The Memory Read command reads data from an agent mapped in the
Memory Address Space. The target is free to do an anticipatory read for
this command only if it can guarantee that such a read has no side
effects.
2.1.2.7 Memory Write Command
The Memory Write command writes data to an agent mapped in the
Memory Address Space. When the target returns “ready”, it assumes
responsibility for the coherency (which includes ordering) of the subject
data.
2.1.2.8 Configuration Read Command
The Configuration Read command reads the configuration space of each
agent. An agent is selected during a configuration access when its
IDSEL signal is asserted and AD[1:0] are 0b00. During the address
phase of a configuration cycle, AD[7:2] address one of the 64 Dword
registers (where byte enables address of the bytes within each Dword)
in the configuration space of each device and AD[31:11] are logical don’t
cares to the selected agent. AD[10:8] indicate which device of a
multifunction agent is being addressed.
2.1.2.9 Configuration Write Command
The Configuration Write command transfers data to the configuration
space of each agent. An agent is selected when its IDSEL signal is
asserted and AD[1:0] are 0b00. During the address phase of a
configuration cycle, the AD[7:2] lines address the 64 Dword registers
(where byte enables address of the bytes within each Dword) in the
configuration space of each device, and AD[31:11] are logical don’t cares
to the selected agent. AD[10:8] indicate which device of a multifunction
agent is addressed.
2.1.2.10 Memory Read Multiple Command
This command is identical to the Memory Read command except that it
additionally indicates that the master may intend to fetch more than one
cache line before disconnecting. The LSI53C876 supports PCI Read
Multiple functionality and issues Read Multiple commands on the PCI