Other Parts Discussed in Thread: SYSBIOS
I am currently testing the mimum delay I can get using GPIOs (in specific WKUP_GPIO0_6, which is connected to TP45) on TDA4VM. I did that for
- Linux (using the gpio consumer interface in a kernel module (PSDKL V07.02.00.07))
- SysBios (using the led_blink example from the pdk (PSDKR V07.02.00.06 and running it on MCU2_0 and MPU1_0)
I was expecting, that the delay for SysBios is significantly smaller than for Linux. However, I observed, that the maximum frequency (On-Off cycle) is
- 20 MHz (Linux, A72)
- 1-2 MHz (SysBios using MCU2_0); 5 MHz (SysBios using MPU1_0)
Even writing directly to register GPIO_SET_DATA01 had no significant improving effect on the output frequency. I could only reach a maximum of 2MHz using MCU2_0 (The effect on MPU1_0 was similiar. I never reached the 20 MHz of Linux).
So comparing the output frequency of this GPIO between Linux and SysBios running both an A72 leads to a factor of 4.
Do you have any explanation for this behaviour? Why is a HLOS faster than a RTOS?
Thanks and best regards