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Reference Manual
Altera Corporation
Stratix II GX PCI Express Development Board
August 2006
Off-Chip Memory
QDRII SRAM
The board uses a burst-of-four QDRII SRAM memory device for
high-speed, low-latency memory access, with addressing for up to a
72-MB device.
The QDRII device has separate read and write data ports with DDR
interfaces at up to 300 MHz. Burst-of-4 devices have higher data rates due
to the longer sequential addressing. The QDRII interface supports over
21 Gb/s of throughput at 300 MHz (600 MB/s x 36 pins). The bandwidth
doubles to over 42 Gb/s when combined read and write bandwidths are
considered.
The QDRII interface signals do not have board-level termination
resistors. Instead, the QDRII interface is terminated using the 50
Ω
output
impedance settings available on both the Stratix II GX device and the
QDRII SRAM device. This approach simplifies board routing and lowers
power consumption.
ddr2_dqs[1]
AU12
ddr2_dqs[2]
AT14
ddr2_dqs[3]
AP15
ddr2_dqs[4]
AV18
ddr2_dqs[5]
AU23
ddr2_dqs[6]
AT25
ddr2_dqs[7]
AU28
ddr2_dqs[8]
AW33
ddr2_odt
AN25
ddr2_rasn
AJ27
ddr2_sync_clk_in
AW20
ddr2_sync_clk_out
AV36
ddr2_wen
AL13
Table 2–30. DDR2 SRAM Pin-Out (Part 5 of 5)
Schematic Signal Name
Stratix II GX Device Pin Number