Sdram Ddr Memory - Alpha Data ADM-XRC-II Pro Hardware Manual

5.3 SDRAM DDR Memory

The XP provides 2 independent banks of 64MB of DDR SDRAM with the option of 128MB when devices
become available. Two Micron MT46V16M16 devices are fitted and are organised as 4Mx16x4. These devices
can be operated at between 75MHz and 133MHz and depending on resource usage within the FPGA, a
2VP70 can easily achieve 100MHz (DDR200) operation. Both banks are driven from Bank2 of the V2Pro.
DDR SDRAM
Bank 0
DQ0[0:15]
DDR
DQS0[0:1]
SDRAM
DQM0[0:1]
DQ0[16:31]
DDR
DQS0[2:3]
SDRAM
DQM0[2:3]
The pins required for the SDRAM controller for each bank are listed below.
The DDR controller uses SSTL1 IOB's for data and control and SSTL1 for address and clocks - Please refer to
the UCF for locations of the DDR pins. Please note that the FPGA requires the Vref pins to be connected for
correct data reception on bank 3 when using SSTL standard. Additionally, bank 4 Vref pins connect to board
Vref but are not required for user applications. These pins should not be configured with pull-up or pull-down
options otherwise the Vref level will be set incorrectly.
The XP is designed to support DDR interface cores supplied by Xilinx using 90 degree phase shifted clocks for
DQS during write operations. This requires DQS pins occupy IOB's that do not share a clock signal with DQ
pins. In the XP, DQS[0:1] and DQS[2:3] occupy pairs of IOB's sharing a common clock. Note A trace delay
has been incorporated on the DQS lines of approx 1.5ns to allow the use of local clocking within the FPGA
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Bank 2
VCCO=2.5V
DDR0_AD/BA/CTL
DDR0_CLK
DDR0_CLKB
DDR0_CLK_FB
2VP70 / 2VP100
FF1704
Name
DDR_ad[0:12]
DDR_dq[0:31]
DDR_dqs[0:3]
DDR_rasb
DDR_casb
DDR_web
DDR_ba[0:1]
DDR_clk
DDR_clkb
DDR_csb
DDR_cke
DDR_dm[0:1]
DDR_clk_fb
DQ1[0:15]
DQS1[0:1]
DQM1[0:1]
DDR1_AD/BA/CTL
DDR1_CLK
DDR1_CLKB
DDR1_CLK_FB
DQ1[16:31]
DQS1[2:3]
DQM1[2:3]
Type
Output
Bidir
Bidir
Output
Output
Output
Output
Output
Output
Output
Output
Output
Input
ADM-XP User Manual
DDR SDRAM
Bank 1
DDR
SDRAM
DDR
SDRAM
ADM-XR-IIPro User Manual
Version 0.2