Vivado已经在.xdc文件中红约束了管脚但还是报错：[DRC NSTD-1]和[DRC UCIO-1]

问题描述：

大致报错信息如下：

[DRC NSTD-1] Unspecified I/O Standard: 13 out of 175 logical ports use I/O standard (IOSTANDARD) value ‘DEFAULT’, instead of a user assigned specific value. This may cause I/O contention or incompatibility with the board power or connectivity affecting performance, signal integrity or in extreme cases cause damage to the device or the components to which it is connected. To correct this violation, specify all I/O standards. This design will fail to generate a bitstream unless all logical ports have a user specified I/O standard value defined. To allow bitstream creation with unspecified I/O standard values (not recommended), use this command: set_property SEVERITY {Warning} [get_drc_checks NSTD-1]. NOTE: When using the Vivado Runs infrastructure (e.g. launch_runs Tcl command), add this command to a .tcl file and add that file as a pre-hook for write_bitstream step for the implementation run. Problem ports: ctrl_in_0[3:0], sync_in_0, o_spi_csn_0, o_spi_mosi_0, clk, o_spi_miso_0, enable_0, en_agc_0, txnrx_0, o_spi_clk_0 and chip_rst_0.

[DRC UCIO-1] Unconstrained Logical Port: 13 out of 175 logical ports have no user assigned specific location constraint (LOC). This may cause I/O contention or incompatibility with the board power or connectivity affecting performance, signal integrity or in extreme cases cause damage to the device or the components to which it is connected. To correct this violation, specify all pin locations. This design will fail to generate a bitstream unless all logical ports have a user specified site LOC constraint defined. To allow bitstream creation with unspecified pin locations (not recommended), use this command: set_property SEVERITY {Warning} [get_drc_checks UCIO-1]. NOTE: When using the Vivado Runs infrastructure (e.g. launch_runs Tcl command), add this command to a .tcl file and add that file as a pre-hook for write_bitstream step for the implementation run. Problem ports: ctrl_in_0[3:0], sync_in_0, o_spi_csn_0, o_spi_mosi_0, clk, o_spi_miso_0, enable_0, en_agc_0, txnrx_0, o_spi_clk_0 and chip_rst_0.

根据提示，I/O口没有进行约束，会造成性能、完整性甚至板卡烧坏，经过对xdc文件进行检查，已经对管脚和I/O标准进行了约束和相应配置。

参考解决方法：

一定是确认已经分配了I/O和相应约束后仍然报这个错误才可参考下面的解决方法！

新建一个.tcl文件，编译如下内容，使Vivado忽略这些未分配的信号：

set_property SEVERITY {Warning} [get_drc_checks NSTD-1]
set_property SEVERITY {Warning} [get_drc_checks UCIO-1]

打开BitStream设置，添加新建的.tcl文件：

然后重新生成bit流文件即可。