
102 www.xilinx.com Spartan-3E FPGA Starter Kit Board User Guide
UG230 (v1.2) January 20, 2011
Chapter 12: SPI Serial Flash
be left floating. Why support multiple packages? In a word, flexibility. The multi-package
layout provides ...
• Density migration between smaller- and larger-density SPI Flash PROMs. Not all
SPI Flash densities are available in all packages. The SPI Flash migration strategy
follows nicely with the pinout migration provided by Xilinx FPGAs.
• Consistent configuration PROM layout when migrating between FPGA densities.
The Spartan-3E FPGA’s FG320 package footprint supports the XC3S500E, the
XC3S1200E, and the XC3S1600E FPGA devices without modification. The SPI Flash
multi-package layout allows comparable flexibility in the associated configuration
PROM. Ship the optimally-sized SPI Flash memory for the FPGA mounted on the
board.
• Supply security. If a certain SPI Flash density is not available in the desired package,
switch to a different package style or to a different density to secure availability.
Figure 12-18: Multi-Package Layout for the STMicroelectronics M25Pxx Family
S
Q
W
GND
VCC
HOLD
C
D
VCC
C
D
HOLD
S
Q
GND
W
(Do not connect)
(Do not connect)
UG230_c15_18_030606
Pin 1:
8-pin SOIC
8-lead MLP
Pin 1:
16-pin SOIC
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