bus_tick block question: each tick = ? system clock ?

[gzleng]

hello, 

i'm trying to calculate the cpu usage. in the process i need to answer the question about "how much time elapsed by 1 bus_tick?" for example, i'm using an external 8mhz crystal on a s32k144 evb with 80Mhz clock. i placed a bus_tick block and read back every second. the diff between reading is 20,000,000 counts per second.. so does it mean there is a /4 from the sys clock? is that configurable?

thanks

gz

[gzleng]

thanks.. great information

[mariuslucianand · Accepted solution]

Hello @gzleng.,

The profiler uses a hardware timer, PIT channel 3, configured to run at 20MHz to count the time elapsed of the subsystem where the profiler blocks are being added. Based on this frequency, a tick is 50 ns long.

Unfortunately, the timer configuration cannot be modified by the user, and it is inserted and configured in the generated code by the toolbox automatically.

Also, I want to recommend you have a look at this particular Community thread. Here we had a great discussion regarding the profiling capabilities and usage: https://community.nxp.com/t5/Model-Based-Design-Toolbox-MBDT/S32k144-Simulation-Time/m-p/1196373#M54... 

Hope this helps,
Marius