Altera GPIO - Manual (Page 19)

Note: The CLK_HR frequency must be half the frequency of CLK_FR. If the clocks are driven by IOPLL,
you may consider using the
derive_pll_clocks
SDC command.
Single Data Rate Output Register
Figure 13: Single Data Rate Output Register
These SDC commands generate the source clock and the output clock to be transmitted:
create_clock -name sdr_out_clk -period "100 MHz" sdr_out_clk
create_generated_clock -source sdr_out_clk -name sdr_out_outclk sdr_out_outclk
This SDC command instructs the TimeQuest timing analyzer to analyze the output data to be transmitted
against the output clock to be transmitted.
set_output_delay -clock sdr_out_clk 0.45 sdr_out_data
DDIO Output Register
The output side of the full-rate and half-rate DDIO output register is the same.
create_clock and create_generated_clock
These SDC commands generate the clocks to the DDIO and the clock to be transmitted:
create_clock -name ddio_out_fr_clk -period "200 MHz" ddio_out_fr_clk
create_generated_clock -source ddio_out_fr_clk -name ddio_out_fr_outclk
ddio_out_fr_outclk
ug-altera_gpio
2014.08.18
Single Data Rate Output Register 19
Altera GPIO IP Core User Guide Altera Corporation
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