LSM9DS1 accelerometer with too many aux pins. Which ones are actually useful?

Question

I'm designign a board with an LSM9DS1. I have an SPI bus (with only this device connected), two gpio for the chip selects (it has two CS, one for gyro and accel and the other for the magnetometer. Weird things happen at ST microelectonics? It has also a separate MISO for the magnetometer, but i guess i can tie them together. At least that's what i saw on the internet. Correct me if i'm wrong)

So now i have a lot of interrupt and enable pin left to be connected, for which the datasheet says too little/nothing. Beeing:

• INT1_A/G: Accelerometer and gyroscope interrupt 1
• INT2_A/G: Accelerometer and gyroscope interrupt 2
• DEN_A/G: Accelerometer and gyroscope data enable
• DRDY_M: Magnetic sensor data ready
• INT_M: Magnetic sensor interrupt

I have only two pins left on my MCU, and i can't wrap my head around, looking only into the datasheet, which ones do i need, which ones can i tie to VCC/GND and which ones are only for specific applications.

Can someone, who has already used it, or can make a sense off what's written on the DS, help me in chosing which pins to keep?

Answer 1

This chip looks like Frankenstein's monster. Magnetometer crammed into existing 6D chip and loosely coupled into register map.

Anyway, DEN_A/G and DRDY_M seem to be bugged. Just leave them alone, DNC.

That leaves you with three interrupt pins, one dedicated to magnetometer and two practically identical (i.e. can generate same interrupts) for accelerometer/gyro. You don't really need any of these, unless your MCU is very busy and you want to reduce polling to minimum.

I guess the choice is yours, whether to have two different A/G interrupts or one A/G and one M.