Altera Corporation
9
APEX 20K Programmable Logic Device Family Data Sheet
Functional
Description
APEX 20K devices incorporate LUT-based logic, product-term-based
logic, and memory into one device. Signal interconnections within
APEX 20K devices (as well as to and from device pins) are provided by the
FastTrack Interconnect—a series of fast, continuous row and column
channels that run the entire length and width of the device.
Each I/O pin is fed by an I/O element (IOE) located at the end of each row
and column of the FastTrack Interconnect. Each IOE contains a
bidirectional I/O buffer and a register that can be used as either an input
or output register to feed input, output, or bidirectional signals. When
used with a dedicated clock pin, these registers provide exceptional
performance. IOEs provide a variety of features, such as 3.3-V, 64-bit,
66-MHz PCI compliance; JTAG BST support; slew-rate control; and
tri-state buffers. APEX 20KE devices offer enhanced I/O support,
including support for 1.8-V I/O, 2.5-V I/O, LVCMOS, LVTTL, LVPECL,
3.3-V PCI, PCI-X, LVDS, GTL+, SSTL-2, SSTL-3, HSTL, CTT, and 3.3-V
AGP I/O standards.
The ESB can implement a variety of memory functions, including CAM,
RAM, dual-port RAM, ROM, and FIFO functions. Embedding the
memory directly into the die improves performance and reduces die area
compared to distributed-RAM implementations. Moreover, the
abundance of cascadable ESBs ensures that the APEX 20K device can
implement multiple wide memory blocks for high-density designs. The
ESB’s high speed ensures it can implement small memory blocks without
any speed penalty. The abundance of ESBs ensures that designers can
create as many different-sized memory blocks as the system requires.
Figure 1 shows an overview of the APEX 20K device.
Figure 1. APEX 20K Device Block Diagram
LUT
Memory
IOE
LUT
Memory
IOE
Product Term
LUT
Memory
IOE
Product Term
FastTrack
Interconnect
Clock Management Circuitry
IOEs support
PCI, GTL+,
SSTL-3, LVDS,
and other
standards.
ClockLock
Four-input LUT
for data path and
DSP functions.
Product-term
integration for
high-speed
control logic and
state machines.
Flexible integration
of embedded
memory, including
CAM, RAM,
ROM, FIFO, and
other memory
functions.