Timing Violation In Half-Rate Bridge Enabled Designs

Description

Timing violation occurs during TimeQuest timing analysis for designs that use the high-performance controller II architecture with the Enable Half Rate Bridge option turned on.

This issue affects all designs that use the high-performance II controller architecture with the Enable Half Rate Bridge option turned on.

Timing violation occurs during compilation in the TimeQuest timing analyzer.

Resolution

Open the altera_avalon_half_rate_bridge_constraints.sdc file in your project directory, and edit the slow_clock variable and add derive_pll_clocks.

• Full-rate design

derive_pll_clocks set slow_clk "*|altpll_component|auto_generated|pll1|clk[1]"

• Half-rate design

derive_pll_clocks

set slow_clk "*|altpll_component|auto_generated|pll1|clk[0]"

This issue will be fixed in a future version of the DDR and DDR2 SDRAM Controllers with ALTMEMPHY IP