ECP5 and ECP5-5G High-Speed I/O Interface
Technical Note
© 2014-2020 Lattice Semiconductor Corp. All Lattice trademarks, registered trademarks, patents, and disclaimers are as listed at
All other brand or product names are trademarks or registered trademarks of their respective holders. The specifications and information herein are subject to change without notice.
22
FPGA-TN-02035-1.3
5.7.
GDDRX1_TX.SCLK.Aligned
This interface is used to implement Generic Transmit DDR with 1x gearing using primary clock (SCLK). The clock output
is aligned to the data output.
This DDR interface uses the following modules:
ODDRX1F element is used to generate the data output
The primary clock (SCLK) is used as the clock for both data and clock generation
Optionally, you can choose to use the DELAYG or DELAYF element to delay the output data
The output data can be optionally tristated using either a Tristate input going through an I/O register.
Figure 5.11. GDDRX1_TX.SCLK.Aligned Interface
Interface Requirement
The clock to the output DDR modules must be routed on the primary clock tree.
5.8.
GDDRX1_TX.SCLK.Centered
Generic Transmit DDR using X1 gearing with SCLK. The clock output is centered to the data output.
This DDR interface uses the following modules:
ODDRX1F element is used to generate the data output
The EHXPLLL element is used to generate the clocks for the data and clock ODDRX1F modules. The clock used to
generate the clock output is delayed 90 to center to data at the output.
Both these clocks are routed on primary clock tree
Optionally, you can choose to use the DELAYG or DELAYF element to delay the output data
The output data can be optionally tristated using either a Tristate input going through an I/O register.