M-.-n
Member
Did anybody manage a way tu compute CPU usage, including code processed at interrupt time ? I'd like to know how much juice I'm sucking out from the GP at various cpu speeds::::
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GP32 Cpu Usage ?
- Thread starter M-.-n
- Start date
Squidge
Certified Guru
The CPU is in the GP32 doesn't have any automatic power management features, so you'll be using 100% all the time, so if you want to know how much current the gp32 uses at particular frequencies, then you just need to place your ammeter between the battery compartment and the pcb (or multimeter in ohms settings with appropriate resistor in +ve path), and measure from there. It'll be the same regardless of the code run, unless you run some power management stuff like telling it to go sleep/etc.
Blah
Wanna Be Programmer
He means CPU (like percentage of load or something) usage, not actual power usage.
Squidge
Certified Guru
percentage of cpu use will always be 100%. If you just want to check the percentage of cpu use that an interrupt uses, then that is possible, or to check the how long a particular routine uses (or set of routines), but it's not possible to see how much "juice is being sucked out". Certainly not at different cpu speeds.
percentage of cpu use will always be 100%. If you just want to check the percentage of cpu use that an interrupt uses, then that is possible, or to check the how long a particular routine uses (or set of routines), but it's not possible to see how much "juice is being sucked out". Certainly not at different cpu speeds.
To test CPU usage in GPMadMp3, I had a debug version that timed certain key routines such as display code, SMC reading code, and most importantly the idle code.
Since the nature of MP3 playback code requires you to do some hanging around, you have some idle time to measure. This should be true with emulation programs as well.
If you know how much time you are spending idle, obviously you can know how much time you are spending doing things.
In theory any code that has to perform tasks before a VSYNC will end up with a idle loop you can use to time.
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M-.-n
Member
I see what u mean... I'm not using VSYNC coz my program is oriented towards audio but I guess I can see how much time I take to prepare an audio buffer versus the physical time that the audio buffer represents. That' ll make a worthwile measurement of how much room I have before I cramp the system.