XC4VFX100-11FFG1152C Datasheet, PDF (5/9 Pages) Xilinx, Inc – Virtex-4 Family Overview

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Virtex-4 Family Overview
range of signal delays. This is especially useful for synchro-
nizing signal edges in source synchronous interfaces.
General purpose I/O in select locations (four per bank) are
designed to be “regional clock capable” I/O by adding spe-
cial hardware connections for I/O in the same locality. These
regional clock inputs are distributed within a limited region
to minimize clock skew between IOBs. Regional I/O clock-
ing supplements the global clocking resources.
Data serializer/deserializer capability is added to every I/O
to support source synchronous interfaces. A serial-to-paral-
lel converter with associated clock divider is included in the
input path, and a parallel-to-serial converter in the output
path.
An in-depth guide to the Virtex-4 FPGA IOB is discussed in
the Virtex-4 FPGA User Guide.
Configurable Logic Blocks (CLBs)
A CLB resource is made up of four slices. Each slice is
equivalent and contains:
• Two function generators (F & G)
• Two storage elements
• Arithmetic logic gates
• Large multiplexers
• Fast carry look-ahead chain
The function generators F & G are configurable as 4-input
look-up tables (LUTs). Two slices in a CLB can have their
LUTs configured as 16-bit shift registers, or as 16-bit distrib-
uted RAM. In addition, the two storage elements are either
edge-triggered D-type flip-flops or level sensitive latches.
Each CLB has internal fast interconnect and connects to a
switch matrix to access general routing resources.
The Virtex-4 FPGA CLBs are further discussed in the
Virtex-4 FPGA User Guide.
Block RAM
The block RAM resources are 18 Kb true dual-port RAM
blocks, programmable from 16K x 1 to 512 x 36, in various
depth and width configurations. Each port is totally synchro-
nous and independent, offering three “read-during-write”
modes. Block RAM is cascadable to implement large
embedded storage blocks. Additionally, back-end pipeline
registers, clock control circuitry, built-in FIFO support, and
byte write enable are new features supported in the Virtex-4
FPGA.
The block RAM feature in Virtex-4 devices is further dis-
cussed in the Virtex-4 FPGA User Guide.
XtremeDSP Slices
The XtremeDSP slices contain a dedicated 18 x 18-bit 2’s
complement signed multiplier, adder logic, and a 48-bit
accumulator. Each multiplier or accumulator can be used
independently. These blocks are designed to implement
extremely efficient and high-speed DSP applications.
The block DSP feature in Virtex-4 devices are further dis-
cussed in XtremeDSP Design Considerations.
Global Clocking
The DCM and global-clock multiplexer buffers provide a
complete solution for designing high-speed clock networks.
Up to twenty DCM blocks are available. To generate
deskewed internal or external clocks, each DCM can be
used to eliminate clock distribution delay. The DCM also
provides 90°, 180°, and 270° phase-shifted versions of the
output clocks. Fine-grained phase shifting offers higher res-
olution phase adjustment with fraction of the clock period
increments. Flexible frequency synthesis provides a clock
output frequency equal to a fractional or integer multiple of
the input clock frequency.
Virtex-4 devices have 32 global-clock MUX buffers. The
clock tree is designed to be differential. Differential clocking
helps reduce jitter and duty cycle distortion.
Routing Resources
All components in Virtex-4 devices use the same intercon-
nect scheme and the same access to the global routing
matrix. Timing models are shared, greatly improving the
predictability of the performance for high-speed designs.
Boundary-Scan
Boundary-Scan instructions and associated data registers
support a standard methodology for accessing and config-
uring Virtex-4 devices, complying with IEEE standards
1149.1 and 1532.
Configuration
Virtex-4 devices are configured by loading the bitstream into
internal configuration memory using one of the following
modes:
• Slave-serial mode
• Master-serial mode
• Slave SelectMAP mode
• Master SelectMAP mode
• Boundary-Scan mode (IEEE-1532)
Optional 256-bit AES decryption is supported on-chip (with
software bitstream encryption) providing Intellectual Prop-
erty security.
DS112 (v3.1) August 30, 2010
www.xilinx.com
Product Specification
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