vhdl code for a pulse

[Deepika.R]

hi friends.. help me write a code for a pulse of 30µs .. its only one pulse .. not periodic pulses ... along with a test bench ..

 

[achaleus]

While writing hdl code you cannot specify time values and even if it simulates it is not synthesizable.
You can generate pulse fo 30 micro sec as
constant pulse_period : time := 30000 ns;
pulse <= 0;
pulse <= not pulse after 40000 ns;
pulse <= not pulse after time;

or you can use wait statements also
as
pulse <= 0;
wait for -----(specify time here);
pulse <= not pulse;
wait for pulse_period;
pulse <= not pulse;