LSI LSI53C895A Technical Manual page 31

2.1.2.2 Special Cycle Command
2.1.2.3 I/O Read Command
2.1.2.4 I/O Write Command
2.1.2.5 Reserved Command
2.1.2.6 Memory Read Command
2.1.2.7 Memory Write Command
2.1.2.8 Configuration Read Command
The LSI53C895A does not respond to this command as a slave and it
never generates this command as a master.
The I/O Read command reads data from an agent mapped in I/O
address space. All 32 address bits are decoded.
The I/O Write command writes data to an agent mapped in I/O address
space. All 32 address bits are decoded.
The LSI53C895A does not respond to this command as a slave and it
never generates this command as a master.
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.
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.
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.
PCI Functional Description 2-5