Altera LVDS SERDES Transmitter / Receiver User Manual
Page 15

Option
Description
What is the outclock divide factor (B)? Specifies the frequency of the
tx_outclock
signal as the
transmitter output data rate divided by the outclock divide
factor (B). For the legal values, refer to the relevant device
handbook.
For a SERDES factor of 5 and 9, the outclock divide factors
available are 1, 5, and 9. The divide factor of 2 is not available.
For Cyclone II devices and later, when the
implement_in_les
parameter is
ON
, the
outclock_duty_cycle
of 50 is not
supported in the following parameter configurations:
• deserialization_factor signal is 5, 7, or 9
•
outclock_divide_by
signal equals to
deserialization_
factor
•
outclock_multiply_by
is 2
Specify phase alignment of 'tx_
outclock' with respect to 'tx_out'
Specifies the phase alignment of
tx_outclock
signal with
respect to the
tx_out
signal. This option is available only if you
use the
tx_outclock
signal.
What is the phase alignment of 'tx_
outclock' with respect to 'tx_out'?
The available values are 0.00, 22.50, 45.00, 67.50, 90.00,
112.50, 135.00, 157.50, 180.00, 202.50, 225.00, 247.50, 270.00,
292.50, 315.00, and 337.50.
The values for this option are device dependent.
This option is available only when you implement the SERDES
in logic cells and uses the
tx_outclock
signal.
What is the outclock duty cycle?
The default value is 50.
The
outclock_duty_cycle
of 50 is not supported when:
•
deserialization_factor
signal is 5, 7, or 9
•
outclock_divide_by
signal equals to
deserialization_
factor
•
outclock_multiply_by
is 2
Use 'tx_locked' output port
Allows you to monitor the lock status of the PLL. The status of
the lock port is identical for the transmitter and receiver when
the IP core uses shared PLLs.
Use 'tx_coreclock' output port
Turn on this option to show the core clock frequency during
simulation. Enables the transmitter core clock signal to the
registers of all the logic that feeds the LVDS transmitter
function. If any other clock feeds the transmit function, your
design must implement the clock domain transfer circuitry.
You must add a false path constraint from the
slow_clock
signal to the
fast_clock
signal in the ALTLVDS_TX IP core
whenever the faster
core_clock
signal implementation is used
for odd deserialization factors.
UG-MF9504
2014.12.15
ALTLVDS_TX Parameter Settings
15
LVDS SERDES Transmitter/Receiver IP Cores User Guide
Altera Corporation