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AR# 46249

Vivado 约束 - 我该如何约束 IDDR/ODDR 接口?

Description

我该如何约束 IDDR/ODDR 接口?

解决方案

在 IDDR/ODDR 应用中,必须指出上升沿和下降沿的 set_output_delay 。

ODDR 示例:

set_output_delay -clock [get_clocks clk_pin_p] -max 1.0 [get_ports {spi_pin}]
set_output_delay -clock [get_clocks clk_pin_p] -max 1.0 [get_ports {spi_pin}] -clock_fall -add_delay
set_output_delay -clock [get_clocks clk_pin_p] -min 0.5 [get_ports {spi_pin}] -add_delay
set_output_delay -clock [get_clocks clk_pin_p] -min 0.5 [get_ports {spi_pin}] -add_delay -clock_fall

IDDR 范例:

set_input_delay -clock [get_clocks clk_pin_p] -max 1.0 [get_ports {spi_pin}]
set_input_delay -clock [get_clocks clk_pin_p] -max 1.0 [get_ports {spi_pin}] -clock_fall -add_delay
set_input_delay -clock [get_clocks clk_pin_p] -min 0.5 [get_ports {spi_pin}] -add_delay
set_input_delay -clock [get_clocks clk_pin_p] -min 0.5 [get_ports {spi_pin}] -add_delay -clock_fall

然后运行了:

report_timing -to [get_ports {spi_pin}] -delay_type max -max_paths 18 -nworst 18
report_timing -from [get_ports {spi_pin}] -delay_type max -max_paths 18 -nworst 18

您将获取 ODDR/IDDR 的上升-上升、上升-下降、下降-下降和下降-上升路径。

AR# 46249
创建日期 01/17/2013
Last Updated 08/22/2013
状态 Active
Type 版本说明
Tools
  • Vivado Design Suite