Intel 845 manual SDR Sdram Interface Signals, Hub Interface Signals

Signal Description

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2.2SDR SDRAM Interface Signals

Signal Name	Type	Description
SCS[11:0]#	O	Chip Select: These signals select the particular SDRAM components
	CMOS	during the active state.
		Note: There are two SCS# signals per SDRAM row. These signals can
		be toggled on every rising system memory clock edge.
SMA[12:0]	O	Multiplexed Memory Address: These signals are used to provide the
	CMOS	multiplexed row and column address to SDRAM.
SBS[1:0]	O	Memory Bank Select: SBS[1:0] define the banks that are selected within
	CMOS	each SDRAM row. The SMA and SBS signals combine to address every
		possible location in a SDRAM device.
SRAS#	O	SDRAM Row Address Strobe: SRAS# is Used with SCAS# and SWE#
	CMOS	(along with SCS#) to define the DRAM commands.
SCAS#	O	SDRAM Column Address Strobe: SCAS# is used with SRAS# and
	CMOS	SWE# (along with SCS#) to define the SDRAM commands.
SWE#	O	Write Enable: SWE# is used with SCAS# and SRAS# (along with SCS#)
	CMOS	to define the SDRAM commands.
SDQ[63:0]	I/O	Data Lines: These signals are used to interface to the SDRAM data bus.
	CMOS
SCB[7:0]	I/O	Check Bit Data Lines: These signals are used to interface to the
	CMOS	SDRAM ECC signals.
SCKE[5:0]	O	Clock Enable: These pins are used to signal a self-refresh or
	CMOS	Powerdown command to a SDRAM array when entering system
		suspend. SCKE is also used to dynamically powerdown inactive SDRAM
		rows. There is one SCKE per SDRAM row. These signals can be toggled
		on every rising SCLK edge.
RDCLKO	O	Clock Output: RDCLKO is used to emulate source-synch clocking for
	CMOS	reads. This signal connects to RDCLKIN.
RDCLKIN	I	Clock Input: RDCLKIN is used to emulate source-synch clocking for
	CMOS	reads. This signal connects to RDCLKO.

2.3Hub Interface Signals

Signal Name	Type	Description
HI_[10:0]	I/O	Hub Interface Signals: Signals used for the hub interface.
	CMOS
HI_STB	I/O	Hub Interface Strobe: One of two differential strobe signals used to
	CMOS	transmit or receive packet data over the hub interface.
HI_STB#	I/O	Hub Interface Strobe Compliment: One of two differential strobe
	CMOS	signals used to transmit or receive packet data over the hub interface.

Intel® 82845 MCH for SDR Datasheet 23