450NX Datasheet, PDF (24/248 Pages) Intel Corporation – Intel 450NX PCIset

2. Signal Descriptions
WSC#
Write Snoop Complete
PCI O
This signal is asserted active to indicate completion of snoop activity on the
system bus on the behalf of the last PCI-DRAM write transaction, and that it
is safe to send the APIC interrupt message.
2.5
Memory Subsystem Interface
The memory subsystem is comprised of the DRAM arrays and the associated RCGs and
MUXs. There is the external interface (between the MIOC and the memory subsystem), and
the internal interface (between the various parts of the memory subsystem.)
2.5.1
External Interface
BANK[2:0]#
Bank Selects
AGTL+ MIOC→ RCG
These signals indicate which memory bank will service this access.
BANK[2:0]# are connected to all RCGs on both memory cards.
CARD[1:0]#
Card Selects
AGTL+ MIOC→ RCG
These signals indicate which memory card will service this access. Valid
patterns in the Intel^® 450NX PCIset are 01b=card0 and 10b=card1, allowing
CARD[0]# to be connected only to card 0 and CARD[1]# to be connected only
to card 1. Each CARD signal is connected to all RCGs on the given memory
card.
CMND[1:0]#
Access Command
AGTL+ MIOC→ RCG
These signals encode the command of the current operation. CMND[1:0]# are
connected to all RCGs on both memory cards.
CSTB#
Command Strobe
AGTL+ MIOC→ RCG
This strobe, when activated, indicates the initiation of an access. This signal is
connected to all RCGs on both memory cards.
MA[13:0]#
Memory Address bus
AGTL+ MIOC→ RCG
These signals define the address of the location to be accessed in the DRAM.,
and are driven on two successive clock cycles to provide up to 28 bits of
effective memory address. The signals are connected to all RCGs on both
memory cards.
ROW#
Row Selects
AGTL+ MIOC→ RCG
These signals indicate which row in the selected memory bank will service
this access. These signals are connected to all RCGs on both memory cards.
GRCMPLT#
Global RCMPLT#
AGTL+, I/O, all RCGs
A “global” version of the RCMPLT(a,b)# signals, asserted coincident with
RCMPLT#, and by the same agent. Whereas each RCMPLT# signal connects
the RCGs on one card with the MIOC, the GRCMPLT# signal connects the
2-12
Intel® 450NX PCIset