MCT8315A: Reserved bit of TRAP_CONFIG1 must be set to 1

Diane Guidez

Part Number: MCT8315A

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

10 months ago

0 Venkatadri Shantaram84961 10 months ago

TI__Mastermind 23462 points

Hi Simon,

Thanks for posting your question.

I will verify this and get back to you.

Thanks and Best Regards

Venkatadri S

0 Venkatadri Shantaram84961 10 months ago in reply to Venkatadri Shantaram84961

TI__Mastermind 23462 points

Hi Simon,

Thanks for allowing time to respond back.

This bit is Align sector selection, here 0 means all LS FETs are turned on and hence Align will not happen properly.

Align means injecting DC current at a proportion on each phase to bring the rotor to a position aligned with respect to D-Axis.

We have reserved this, because changing default will causes align will not work.

Thanks and Best Regards

Venkatadri S

0 Diane Guidez 10 months ago in reply to Venkatadri Shantaram84961

Prodigy 20 points

Hi Venkatadri,

Thanks for your detailed response.

Indeed, we have to be more careful regarding these reserved bits. I will check recommended default value if other reserved bits shall be also set to 1.

For your information, the value 2h for DIR_INPUT of register PIN_CONFIG1 is missing in the datasheet of MCT8315A. It seems that this value allows to set counterclockwise rotation

Best regards

Simon

Motor drivers

Motor drivers forum

MCT8315A: Reserved bit of TRAP_CONFIG1 must be set to 1