vivado2019.1使用总结之bit文件生成报错_[drc nstd-1] unspecified i/o standard: 2 out of 4

1、vivado的ila报错问题

1、[DRC NSTD-1] Unspecified I/O Standard: 1 out of 136 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: clk_sel.

问题分析：

根据报错信息知道，因为顶层文件的输出端口的电平标准或者有些没有锁定导致的，例如上面的就是 clk_sel这个输出端口没有锁定，电平标准也没有导致的，修改即可解决。