Datasheet

Signal Description
2-2 Intel
®
E8870 Scalable Node Controller (SNC) Datasheet
Some signals or groups of signals have multiple versions. These signal groups may represent
distinct but similar ports or interfaces, or may represent identical copies of the signal used to reduce
loading effects. Table 2-3 shows the conventions SNC use
.
Only the PLL power-supply signals are listed. No other power-supplies are listed.
Typically, upper case groups, (“A, B, C”) represent functionally similar but logically distinct
signals. Each signal provides an independent control and may or may not be asserted at the same
time as the other signals in the grouping. In contrast, lower case groups, (“a, b, c”) typically
represent identical duplicates of a common signal. Such duplicates are provided to reduce loading.
2.2 SNC Signal List
Table 2-4 lists all of the SNC signals.
Table 2-2. Buffer Signal Directions
Buffer Direction Description
I Input signal.
O Output signal.
OD Output open drain.
I/O Bidirectional (input/output) signal.
SBD Simultaneous Bi-directional signal.
Table 2-3. Signal Naming Conventions
Convention Expands To
RR{0/1/2}XX Expands to: RR0XX, RR1XX, and RR2XX.
RR[2:0] Expands to: RR[2], RR[1], and RR[0]. This denotes a bus.
RR# or RR[2:0]# Denotes an active low signal or bus.
Table 2-4. SNC Signal List
Signal Type Frequency Description
Main Channels 0, 1, 2, 3
R{0/1/2/3}DQA[8:0]
I /O
RSL
800 MHz
RAMBUS Data(A)
Data signals used for read and write operations on RAMBUS data
bus “A”.
R{0/1/2/3}DQB[8:0]
I/O
RSL
800 MHz
RAMBUS Data(B)
Data signals used for read and write operations on RAMBUS
databus “B”.
R{0/1/2/3}RQ[7:0]
O
RSL
800 MHz
Request Control Signals
R{0/1/2/3}RQ[7:0] are used for sending control packets on
RAMBUS channel. The RAMBUS specification defines the
mapping of RAMBUS packets to these lines for RDRAM. The DMH
Component Specification defines the mapping for DDR.
R{0/1/2/3}EXRC
O
RSL
800 MHz
Row Expansion Signal
These signals are not used by SNC.