EP20K400CF672C7 Altera, EP20K400CF672C7 Datasheet - Page 47

• Manufacturer Part Number: EP20K400CF672C7
• Description: APEX 20KC
• Manufacturer: Altera

APEX 20KC Programmable Logic Device Data Sheet
Clock Multiplication
The APEX 20KC ClockBoost circuit can multiply or divide clocks by a
programmable number. The clock can be multiplied by m/(n × k), where
m and k range from 2 to 160 and n ranges from 1 to 16. Clock multiplication
and division can be used for time-domain multiplexing and other
functions, which can reduce design LE requirements.
Clock Phase & Delay Adjustment
The APEX 20KC ClockShift feature allows the clock phase and delay to be
adjusted. The clock phase can be adjusted by 90° steps. The clock delay
can be adjusted to increase or decrease the clock delay by an arbitrary
amount, up to one clock period.
LVDS Support
All APEX 20KC devices support differential LVDS buffers on the input
and output clock signals that interface with external devices. This is
controlled in the Quartus II software by assigning the clock pins with an
LVDS I/O standard assignment.
Two high-speed PLLs are designed to support the LVDS interface. When
using LVDS, the I/O clock runs at a slower rate than the data transfer rate.
Thus, PLLs are used to multiply the I/O clock internally to capture the
LVDS data. For example, an I/O clock may run at 105 MHz to support
840 Mbps LVDS data transfer. In this example, the PLL multiplies the
incoming clock by eight to support the high-speed data transfer. You can
use PLLs in EP20K400C and larger devices for high-speed LVDS
interfacing.
Lock Signals
The APEX 20KC ClockLock circuitry supports individual LOCK signals.
The LOCK signal drives high when the ClockLock circuit has locked onto
the input clock. The LOCK signals are optional for each ClockLock circuit;
when not used, they are I/O pins.
Altera Corporation
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