
Altera Corporation
10–29
July 2005
Stratix Device Handbook, Volume 2
Transitioning APEX Designs to Stratix & Stratix GX Devices
channel as an output clock to an I/O pin, not just dedicated clock output
pins. This solution offers better versatility to address various applications
that require more complex clocking schemes.
f
For more information on differential I/O support, data realignment, and
the transmitter clock output in Stratix and Stratix GX devices, see the
High-Speed Differential I/O Interfaces in Stratix Devices chapter.
altlvds Megafunction
To take full advantage of the high-speed differential I/O standards
available in Stratix and Stratix GX devices, you should update each
instance of the altlvds megafunction in APEX II, APEX 20KE, and
APEX 20KC designs. In the MegaWizard Plug-In Manager, choose the
altlvds
megafunction, select Stratix or Stratix GX as the target device
family, update the megafunction, and recompile your design.
The altlvds megafunction supports new Stratix and Stratix GX
parameters that are not available for APEX II, APEX 20KE, and
parameters for the LVDS receiver and LVDS transmitter, respectively.
Table 10–11. New altlvds Parameters for Stratix LVDS Receiver Note (1) Parameter
Function
input_data_rate
Specifies the data rate in Mbps. This parameter replaces the
multiplication factor W.
inclock_data_alignment
Indicates the alignment of rx_inclk and rx_in data.
rx_data_align
Drives the data alignment port of the fast PLL and enables byte
realignment circuitry.
registered_data_align_input
Registers the rx_data_align input port to be clocked by
rx_outclock
.
common_rx_tx_pll
Indicates the fast PLL can be shared between receiver and transmitter
applications.
Table 10–12. New altlvds Parameters for Stratix LVDS Transmitter (Part 1 of 2) Note (1) Parameter
Function
output_data_rate
Specifies the data rate in Mbps. This parameter replaces the
multiplication factor W.
inclock_data_alignment
Indicates the alignment of tx_inclk and tx_in data.
outclock_alignment
Specifies the alignment of tx_outclock and tx_out data.