Siemens TC65 - Manual (Page 29)

TC65 JAVA User's Guide
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TC65 JAVA User's Guide_V05 Page 29 of 90 26.09.2005
5.9 Performance
The performance study was focused on comparable performance values under various
circumstances.
5.9.1 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
Î Java instruction execution
Î reaction on GPIO).
Generated frequency A
[reference sequence]
Test MIDlet
Output pin
Change
output
pin level
Measurement loop (for frequency B)
Send URC (start performance test) ATCommandListener.ATEvent()
Generated frequency B
[measurement sequence]
ATCommand.send(...)
Measurement sequence
Reference loop (for frequency A)
ATCommand.send(...)
Figure 11: 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
measurement sequence is moved.
State jPS-Value (mean)
TC65 module in IDLE mode / Not connected ~49000
CSD connection ~46000
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.