AC Induction Motor Example
C2000 Microcontroller Workshop - Numerical Concepts 8 - 33
AC Induction Motor Example
Performance comparisons
Benchmark C28x C C28x C C28x C
floating-point floating-point IQmath
std. RTS lib fast RTS lib v1.4d
(150 MHz) (150 MHz) (150 MHz)
B1: ACI module cycles 401 401 625
B2: Feedforward control cycles 421 371 403
B3: Feedback control cycles 2336 792 1011
Total control cycles (B2+B3) 2757 1163 1414
% of available MHz used 36.8% 15.5% 18.9%
(20 kHz control loop)
Notes: C28x compiled on codegen tools v5.0.0, -g (debug enabled), -o3 (max. optimization)
fast RTS lib v1.0beta1
IQmath lib v1.4d
Using the profiling capabilities of the respective DSP tools, the table above summarizes the num-
ber of cycles and code size of the forward and feedback control blocks.
The MIPS used is based on a system sampling frequency of 20 kHz, which is typical of such sys-
tems.