Get memory dump in ModelSim (periodical)

Question

How can I get memory dump in ModelSim on a regular basis?

I know how to export memory data. Is there a way to write in the .do file a command to export the memory data every 1000 ns or every x cycles?

Update:

Thanks for the answers. The way I'm doing it now:

mkdir -p mlog
set counter 0
set limit 30

while { true } {
   run 100 us
  incr counter +1
  mem save -o ./mlog/spram1_${counter}.mem -f mti -data binary -addr hex /ram_tb/spram1/mem
  mem save -o ./mlog/spram2_${counter}.mem -f mti -data binary -addr hex /ram_tb/spram2/mem
  /path/to/third/mem
}

This is in case you used run -all before and you don't know when the simulation stops. The VHDL testcase should of course have something like

ASSERT false
    REPORT "### End of Simulation!"
    SEVERITY failure;

to end the simulation (for a nicer way see the answers below, but this works)

In case you know how long the simulation will run you can also use this way:

  mkdir -p mlog
  set counter 0
  set limit 10

  while { $counter < $limit } {
    run 1 ns
    incr counter +1
    mem save -o ./mlog/filename1_${counter}.mem -f mti -data binary -addr hex /path/to/another/mem
    mem save -o ./mlog/filename2_${counter}.mem -f mti -data symbolic -addr hex -wordsperline 1 /path/to/mem
    ## mem save -o ./mlog/anotherfile ...
  }

that can replace "run 10 ns"

alternatively you can use a signal that indicates the end of simulation

  signal end_of_sim   : std_logic := '0';
  ...
  end_of_sim <= '1'

and in the do-file:

  when -label end_of_simulation {/end_of_sim == '1'} {
    echo "End of simulation"; 
    stop ;
    #quit -f
  }

Answer 1

It's not a brilliant solution for your problem, but it could help you a bit.

In a TCL while loop you can do this two command:

while ... {
    run 100 ns;
    mem save -outfile $filename...
}

Note that a Modelsim DO file is a TCL file.

A better solution would be to add the dump of the memory in the 'onbreak' function.

onbreak {mem save ...}

Whenever you break or stop the simulation, the content of the RAM will be saved. Then you still need a trigger to break the simulation. Somebody?