R
Architectural Overview
The Spartan-3E family architecture consists of five funda-
mental programmable functional elements:
•
Digital Clock Manager (DCM) Blocks provide
self-calibrating, fully digital solutions for distributing,
delaying, multiplying, dividing, and phase-shifting clock
signals.
•
Configurable Logic Blocks (CLBs) contain flexible
Look-Up Tables (LUTs) that implement logic plus
storage elements used as flip-flops or latches. CLBs
perform a wide variety of logical functions as well as
store data.
These elements are organized as shown in Figure 1. A ring
of IOBs surrounds a regular array of CLBs. Each device has
two columns of block RAM except for the XC3S100E, which
has one column. Each RAM column consists of several
18-Kbit RAM blocks. Each block RAM is associated with a
dedicated multiplier. The DCMs are positioned in the center
with two at the top and two at the bottom of the device. The
XC3S100E has only one DCM at the top and bottom, while
the XC3S1200E and XC3S1600E add two DCMs in the
middle of the left and right sides.
•
Input/Output Blocks (IOBs) control the flow of data
between the I/O pins and the internal logic of the
device. Each IOB supports bidirectional data flow plus
3-state operation. Supports a variety of signal
standards, including four high-performance differential
standards. Double Data-Rate (DDR) registers are
included.
•
•
Block RAM provides data storage in the form of
18-Kbit dual-port blocks.
Multiplier Blocks accept two 18-bit binary numbers as
inputs and calculate the product.
The Spartan-3E family features a rich network of traces that
interconnect all five functional elements, transmitting sig-
nals among them. Each functional element has an associ-
ated switch matrix that permits multiple connections to the
routing.
Notes:
1. The XC3S1200E and XC3S1600E have two additional DCMs on both the left and right sides as
indicated by the dashed lines. The XC3S100E has only one DCM at the top and one at the bottom.
Figure 1: Spartan-3E Family Architecture
4
www.xilinx.com
DS312-1 (v3.8) August 26, 2009
Product Specification
XILINX [ XILINX, INC ]
