Indirect Spi; Example Of Direct Spi Topology - Xilinx Platform Cable USB II Manual

X-Ref Target - Figure 18
+2.5V +3.3V
Spartan-3E
FPGA
GND
Notes:
1. The pin names for a ST Microsystems M25Pxx serial flash device are shown in this example. SPI flash devices from other vendors can have
different pin names and requirements. Refer to the SPI flash data sheet for the equivalent pins and device requirements.
2. The example shows the interconnect and device requirements for a Xilinx Spartan-3E FPGA. Other SPI-capable FPGAs can have different
pin names and requirements. Please refer to the FPGA data sheet for equivalent pins and device requirements.
3. The cable uses an open-drain driver to control the pseudo ground (PGND) signal — an external pull-up resistor is required.
4. Attach the following 2-mm connector pins to digital ground: 3, 5, 7, 9 and 11.
5. Typically, an FPGA and other slave SPI devices (not shown) are connected to the SPI bus. The other devices on the SPI bus must be disabled
when the cable is connected to the 2-mm connector to avoid signal contention. When a Xilinx FPGA is connected to the SPI bus, the cable
holds the FPGA PROG_B pin Low to insure the FPGA SPI pins are 3-stated.

Indirect SPI

When used with Xilinx design tools, Platform Cable USB II can be used to indirectly program some third-party SPI serial
flash PROMs via the target FPGA's JTAG port. For a complete description on using Platform Cable USB II for indirect
programming of third-party SPI serial flash PROMs and for a complete list of supported SPI serial flash memories, refer to
XAPP974, Indirect Programming of SPI Serial Flash PROMs with Spartan-3A FPGAs.
Indirect BPI
When used with Xilinx design tools, Platform Cable USB II can be used to indirectly program Platform Flash XL, or some
third-party NOR flash memories (BPI PROMs) via the target FPGA's JTAG port. For a description of the indirect Platform
Flash programming solution, see UG438, Platform Flash XL User Guide.
DS593 (v1.2.1) March 17, 2011
+1.2V
MOSI
SPI Bus
DIN
(2)
CSO_B
CCLK
PROG_B
Figure 18: Example of Direct SPI Topology
+ 3.3V
(5)
+ 2.5V
www.xilinx.com
Platform Cable USB II
2 mm
Connector
V
2
REF
8 MISO
10 MOSI
4 SS
6 SCK
13 PGND
* (4)
GND
+3.3V
VCC
D
ST Micro
Q
(1)
M25Pxx
SPI Flash
S
HOLD
C
GND
W '1'
'1'
DS593_18_021508
18