MCT8315A: Reserved bit of TRAP_CONFIG1 must be set to 1

Tool/software:

Hi,

I use a MTC8315AIV on a custom board and I have a strange behavior when I configure EEPROM register TRAP_CONFIG1 .

According to the datasheed the bit 19 of TRAP_CONFIG1 is reserved and I would expect that its value would be ignored as it it inside a configurable register.

But when I set 0, the motor does not start and when this bit is set to 1, the motor starts normally.

Can you please tell me if this observed behavior is normal?

Thanks,

Simon