Digilent NetFPGA-SUME Referenzhandbuch - Seite 14

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NetFPGA-SUME™ Reference Manual



dsumecfg will not work properly if an FMC card that inserts a JTAG device into the scan chain is attached

to the NetFPGA-SUME.

Memory

4.1

DDR3 SODIMM

The NetFPGA-SUME board comes with two Micron MT8KTF51264HZ-1G9 4GB DDR3 SDRAM SODIMM, which

employs an 932.84MHz 64bit-wide data bus capable of operating at a data rate of 1866MT/s. Project development

with the SDRAM involves using the Xilinx Memory Interface Generator (MIG) in Vivado Design Suite. The interface

is automatically configured by the MIG for use with the AXI4 system bus and provide a fixed 4:1 memory to bus

clock ratio. The input clock for both SDRAM SODIMMs is a 233MHz clock generated by Discera DSC1103 Low Jitter

Precision LVDS Oscillator. The clock period of SDRAM is configured to 1177ps (849.62MHz), equivalent to

1700MT/s, due to the read margin issues. Please refer to Xilinx

The NetFPGA-SUME uses a VCC

see

Xilinx 7 Series FPGAs Memory Interface Solutions User Guide (UG586)

204-Pin DDR3L SODIMM

datasheet for more details. The DDR3 project in unit test project in netfpga repository

provides a good starting point for project development.

4.2

QDRII+ SRAM

Three Cypress CY7C25652KV18 Quad Data Rate II+ (QDRII+) SRAMs are provided for applications that require high

speed, low latency memory. Each component provides a 36 bit wide data bus and has a density of 72 Megabits.

Common applications include FIFO buffers and look-up tables. The notion of "Quad" data rate comes from the

ability to simultaneously read from a unidirectional read port and write to a unidirectional write port on both clock

edges. The QDRII+ SRAMs on NetFPGA-SUME board are capable of operating at up to 500MHz to yield data

transfer rates of up to 1GT/s per 36-bit wide data bus. The Xilinx Memory Interface Generator (MIG) is able to

generate and configure a native interface into the QDRII+ via the user friendly wizard tool. More information

regarding the QDRII+ memory part and the Xilinx MIG tool can be found in the Cypress

CY7C25632KV18/CY7C25652KV18 datasheet, the Cypress Application Note QDR-II, QDR-II+, DDR-II, DDR-II+ Design

Guide (AN4065), and the Xilinx 7-Series FPGA Memory Interface Solutions User Guide (UG586).

QDRA and QDRB share FPGA bank 17, which means that in order to access them simultaneously, a bank sharing

solution must be used that extends beyond the default functionality of the MIG. This solution is still currently being

developed. Please refer to Xilinx Answer Record 41706 for further information.

Storage

5.1

FLASH

Onboard parallel flash is available for storing FPGA bitstreams. For information on writing bitstreams to flash and

configuring the FPGA from stored bitstreams, see the section titled

Other product and company names mentioned may be trademarks of their respective owners.

of 2.0V to support high performance DDR3 frequency settings. Please

AUX-IO

Answer Record AR61853

for further information.

and the micron

1GB, 2GB, 4GB (x64, SR)

"Configuration using Parallel

Flash".

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