Embedded Developer

Lately, on STM page I have found out they put Coremark scores on brochures for the microcontrollers.  I was wondering what competitors scores, so I couldn't find anything for Texas Instrument. On https://www.eembc.org/ I have found out there is a source code of Caremark which can be ported on any platform, so I decided to port it on Tiva TM4C123GH6PM and test it. Here are the results: 2K performance run parameters for coremark. CoreMark Size    : 666 Total ticks      : 19775 Total time (secs): 19.774999 Iterations/Sec   : 101.1378 Iterations       : 2000 Compiler version : GCC7.2.1 20170904 (release) [ARM/embedded-7-branch revision 255204] Compiler flags   : Memory location  : STACK seedcrc          : 0xe9f5 [0]crclist       : 0xe714 [0]crcmatrix     : 0x1fd7 [0]crcstate      : 0x8e3a [0]cr...

Lately, I was working with IIR filter so in CMSIS repo I saw look-up table with sinus value. I was wondering how much faster it works then math.h sinus function. The name of the function which uses a lookup table is arm_sin_f32() which is part of  arm_math.h Lets first compare results calculated with the lookup table and math.h sin function. Result2 are from the lookup table (arm_sin_f32() -> arm_math.h) and result1 are from sinus function (sin() -> math.h). From results is seen that after decimal point 4-5 digits are similar so take care with that.  I have done an iteration of 100 000 calculation and I was measuring the time needed for math.h sin and got 9726 [ms], and for arm_math.h 2006 [ms] which is almost 5x time faster.  In the photo below I added sinus wave for both calculations. Blue is result1 and red is result2. You can see they overlap.  You can check the code on the link . 

Here is the git repo where I paired two Time of Flight (ToF) sensors VL53L1X and VL53L0X to the TM4C123GXL development board.