I would like to use the TIMROT v2 module TIMER3 in duty cycle measurement mode.
As a first test, I just want to measure the duty cycle of the 32 kHz crystal clock.
As the clock tick input, I select TICK_ALWAYS (0xF)
As the test input, I select the 32 kHz crystal clock (0xB)
root@imx28evk:~# devmem2 0x800680e0 w 0x000b02cf
However, the DUTY_VALID does not go high as I would expect (i.e. the test signal is an approx. 50/50 duty cycle signal).
IRQ goes high, and LOW_RUNNING_COUNT gets a value, but HIGH_RUNNING_COUNT does not.
Read at address 0x800680E0: 0x000B82CF
Read at address 0x800680F0: 0xF1F83AD9
Read at address 0x80068100: 0x00000000
- It is not documented how UPDATE and RELOAD bits must be set in duty cycle mode.
- It is not documented how IRQ is handled in duty cycle mode
- Must I preload the FIXED_COUNT register to 0xffffffff?
Thanks for any insights to get this working,