18 | ni.com | NI Digital System Development Board User Manual
SPI Flash
The DSDB features a Quad-SPI serial flash device, the Spansion S25FL128S. The Multi-I/O SPI
Flash memory is used to provide non-volatile code and data storage. It can be used to initialize
the PS subsystem as well as configure the PL subsystem (bitstream).
The relevant device attributes are:
• 128 Mbit
• x1, x2, and x4 support
• Speeds up to 94 MHz. In Quad-SPI mode, this translates to 376 Mbps
• Powered from 3.3 V
The SPI Flash connects to the Zynq-7000 AP SoC supporting up to Quad-I/O SPI interface. This
requires connection to specific pins in MIO Bank 0/500, specifically MIO[1:6,8] as outlined in
the Zynq datasheet. Quad-SPI feedback mode is used, thus qspi_sclk_fb_out/MIO[8] is left to
freely toggle and is connected only to a 20K pull-up resistor to 3.3 V. This allows a QSPI clock
frequency greater than FQSPICLK2.
Table 5. NI ELVIS Zynq Connections
NI ELVIS Pin Breadboard Header Breadboard Pin
+15V Power +15V
-15V Power -15V
+5V Power +5V
VPS+ Power VPS+
VPS- Power VPS-
AIGND Analog AIGND
AISENSE Analog AISNS
AO0 Analog AO0
AO1 Analog AO1
AI0+ Analog AI0+
AI0- Analog AI0-
AI1+ Analog AI1+
AI1- Analog AI1-
AI2+ Analog AI2+
AI2- Analog AI2-