How to control the XTA from a python script

• version

  1.1.1

• scope

  Example.

  This code is provided as example code for a user to base their code on.

• description

  How to control the XTA from a python script

• boards

  Unless otherwise specified, this example runs on the SliceKIT Core Board, but can easily be run on any XMOS device by using a different XN file.

There are occasions when the inbuilt XTA command scripting mechanism does not offer the required level of power and/or flexibility. For example, you may wish to pass arguments to a script, use the return value of one command as input to another or make use of conditional/looping constructs. With this in mind, the XTA provides an interface which allows the tool to be controlled from Python scripts.

For example, compile the following code:

#include <stdlib.h>
#include <xs1.h>

port p1 = XS1_PORT_1A;
port p2 = XS1_PORT_1B;

int main() {
  int x;

  #pragma xta endpoint "input"
  p1 :> x;

  // Checks for errors..
  if (x == 1) {
    #pragma xta label "error_case"
    exit(1);
  }

  // do some computation here..

  #pragma xta endpoint "output"
  p2 <: 0;
  return 0;
}

As an example, assume that you want to time from the input to the output, set a requirement and exclusion, and this this must be done from a Python script. To achieve this, place the following lines in a file, e.g. script.py:

import java

try:
  xta.load("a.xe") ;

except java.lang.Exception, e:
  print e.getMessage()

try:
  xta.addExclusion("error_case")
  ids = xta.analyzeEndpoints("input", "output")
  for id in ids:
    print xta.getRouteDescription(id) + ":",
    print xta.getWorstCase(id, "ns"),

except java.lang.Exception, e:
  print e.getMessage()

The above script can then be run using the XTA source command:

xta source script.py -exit

Note: See the XMOS-Timing-Analyzer-Manual for further information on available interface methods.