EP2C5F256C7N Datasheet, PDF (49/168 Pages) Altera Corporation – Section I. Cyclone II Device Family Data Sheet

Cyclone II Architecture
f
There are five dynamic control input signals that feed the embedded
multiplier: signa, signb, clk, clkena, and aclr. signa and signb
can be registered to match the data signal input path. The same clk,
clkena, and aclr signals feed all registers within a single embedded
multiplier.
For more information on Cyclone II embedded multipliers, see the
Embedded Multipliers in Cyclone II Devices chapter.
I/O Structure &
Features
IOEs support many features, including:
■ Differential and single-ended I/O standards
■ 3.3-V, 64- and 32-bit, 66- and 33-MHz PCI compliance
■ Joint Test Action Group (JTAG) boundary-scan test (BST) support
■ Output drive strength control
■ Weak pull-up resistors during configuration
■ Tri-state buffers
■ Bus-hold circuitry
■ Programmable pull-up resistors in user mode
■ Programmable input and output delays
■ Open-drain outputs
■ DQ and DQS I/O pins
■ V_REF pins
Cyclone II device IOEs contain a bidirectional I/O buffer and three
registers for complete embedded bidirectional single data rate transfer.
Figure 2–20 shows the Cyclone II IOE structure. The IOE contains one
input register, one output register, and one output enable register. You can
use the input registers for fast setup times and output registers for fast
clock-to-output times. Additionally, you can use the output enable (OE)
register for fast clock-to-output enable timing. The Quartus II software
automatically duplicates a single OE register that controls multiple
output or bidirectional pins. You can use IOEs as input, output, or
bidirectional pins.
Altera Corporation
February 2007
2–37
Cyclone II Device Handbook, Volume 1