Spatan3e系列最高工作频率达333MHz，可用来设计PCI接口；支持SPI配置模式；逻辑门数相对较少，2M以下，相对成本较低；Spatan3e有ODDR2组件，而spatan3不支持。

以下为网上资料摘抄：

* Spartan-3E family complements the Spartan-3 family – Spartan-3E optimized
for gate-centric designs with less than 2M gates, Spartan-3 optimized for I/Ocentric
designs from 1M to 5M gates

*Other Cost Saving Features: Spartan-3E devices include a built-in interface to
commonly used DDR333 memory. Also, the minimum DCM input frequency is
lowered to 5 MHz (Spartan-3 DCM min. input frequency is 24 MHz) enabling the
use of lower cost oscillators. Up to eight DCMs are available to eliminate discrete
DLL/PLL/phase shifter/clock management devices.

Choosing Between Spartan-3E and Spartan-3 Families
14. Does the Spartan-3E family replace the Spartan-3 family?
No, the Spartan-3E and Spartan-3 FPGA families are complementary: each is designed
to provide the best ratio of gates to I/Os for different applications. Spartan-3E FPGAs
are optimized for gate-centric (higher ratio of gates to I/Os) designs with under 2M
gates while Spartan-3 FPGAs are optimized for I/O-centric (higher ratio of I/Os to
gates) designs from 1M to 5M gates.
16. What are the feature differences between Spartan-3E and Spartan-3 families?
There are a few feature differences between the Spartan-3E and Spartan-3 families that
can determine which family to target for a new design. Spartan-3 devices in the
density range under 2 million gates (XC3S50 to XC3S1500) should be targeted if any of
the following “Spartan-3 only” features are needed:
• Digitally Controlled Impedance (DCI) also known as XCITE
• High current I/O standards over 16 mA
• I/O standards – GTL/GTL+/HSTL I/HSTL III/HSTL18 III/SSTL2
II/LDT/LVDS_ext
• Low-power option (Spartan-3L)
Spartan-3E devices should be targeted if any of the following “Spartan-3E only”
features are needed:
• Serial (SPI) or parallel flash memory used for configuration
• PCI 66 MHz compliance, PCI-X compatibility and mini-LVDS I/O standard
support
• DDR333 memory interface
• Fully pipelined embedded multiplier performance to 325 MHz
• Eight DCMs with 5 MHz minimum input frequency