Kinetis V - Hall sensor decoder mode

[gregprusaitis]

The KV4x Reference Manual (Chapter 40: FlexTimer Module) mentions “CnSC[ICRST] is available only on FTM1, which has Hall sensor decoder mode.” But not nothing else is said about Hall sensor decoder mode in this manual. Is there a document that gives more detail about this mode?

Does the hall interface have features such as checks for invalid states and next expected state?

[xiangjun_rong]

Hi, Greg,

As you know that you have to use three hall sensors to detect the rotor position, you can connect the three hall sensors output signals to the FTM1_CH0(PTE20), FTM1_CH1(PTE21), the other hall output signals to any crossbar input pin XB_INx, for example XB_IN2(PTE24) so that you can use crossbard to route the signal to FTM1_CH1. Furthermore, you can set the FTM1ICH1SRC bit in SIM_SOPT9 so that the three hall signals are EXORed and output the exored signal to FTM1_CH1. You can set the pin in capture mode so that the rising/falling edge can trigger interrupt to switch the stator for BLDC motor control in capture ISR and use the captured value to compute the speed.

Regarding the hall signal logic you have to read, i think you can read the GPIOE_PDIR to get the logic even if you do not configure the pin in GPIO mode. But I am not very sure for all pin, pls confirm yourself.

Pls refer to FTM/SIM and XBARA chapters in reference manual of KV4X.

Hope it can help you.

BR

Xiangjun Rong