Datasheet

Signal Description
Intel
®
Xeon
®
and Intel
®
Core™ Processors For Communications Infrastructure
May 2012 Datasheet - Volume 1 of 2
Document Number: 327405
-001 71
8.0 Signal Description
This chapter describes the processor signals. They are arranged in functional groups
according to their associated interface or category. The following notations are used to
describe the signal type:
The signal description also includes the type of buffer used for the particular signal.
8.1 System Memory Interface
Notations Signal Type
IInput Pin
OOutput Pin
I/O Bi-directional Input/Output Pin
Table 8-1. Signal Description Buffer Types
Signal Description
PCI Express*
PCI Express* interface signals. These signals are compatible with PCI Express* 2.0
Signalling Environment AC Specifications and are AC coupled. The buffers are not 3.3-
V tolerant. See the PCIe* specification.
DMI
Direct Media Interface signals. These signals are compatible with PCI Express* 2.0
Signaling Environment AC Specifications, but are DC coupled. The buffers are not 3.3-
V tolerant.
CMOS CMOS buffers. 1.1-V tolerant
DDR3 DDR3 buffers: 1.5-V tolerant
A
Analog reference or output. May be used as a threshold voltage or for buffer
compensation
Ref Voltage reference signal
Asynchronous
1
Signal has no timing relationship with any reference clock.
Notes:
1. Qualifier for a buffer type.
Table 8-2. Memory Channel A (Sheet 1 of 2)
Signal Name Description
Direction/Buffer
Type
SA_BS[2:0]
Bank Select: These signals define which banks
are selected within each SDRAM rank.
O
DDR3
SA_WE#
Write Enable Control Signal: Used with
SA_RAS# and SA_CAS# (along with SA_CS#) to
define the SDRAM Commands.
O
DDR3
SA_RAS#
RAS Control Signal: Used with SA_CAS# and
SA_WE# (along with SA_CS#) to define the SRAM
Commands.
O
DDR3