Siemens XT65 - Manual (Page 43)

Java User’s Guide
5.12 Performance
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wm_java_usersguide_v12 Page 43 of 123 2008-02-25
Confidential / Released
5.12 Performance
The performance study was focused on comparable performance values under various circum-
stances.
5.12.1 Java
This section gives information about the Java command execution throughput (“jPS”= Java
statements per second). The scope of this measurement is only the statement execution time,
not the execution delay (Java command on AT interface
→ Java instruction execution →
reac-
tion on GPIO).
Figure 13: Test case for measuring Java command execution throughput
The following Java instruction was used for calculation of the typical jPS:
value = ( 2 x number of calculation statements ) /
( (1 / frequencyB ) - ( 1 / frequencyA ) );
Measurement and calculation were done using:
•
duration of each loop = 600 s
• number of calculation statements = 50 “result=(CONSTANT_VALUE/variable_value);”-
Instructions (executed twice per pin cycle)
• frequencyA as measured with a universal counter
• frequencyB as measured with a universal counter
The reference loop has the same structure as the measurement loop except that the measure-
ment sequence is moved.
Since only a small amount of Java code is executed in this test, it is easily optimized by the
CLDC’s HI just-in-time compiler. More complex applications might not reach that execution
speed.
State jPS-Value (mean)
ME in IDLE mode / Not connected ~49000
CSD connection ~46000