MSP430F5659: Abnormal restart problem

Lumina Gui

Part Number: MSP430F5659

Hi Sir,

Our customer reported that they use MSP430F5659 to connect to the G-SENSOR chip through the P2.7/P2MAP7 pin, and G_EN will instantly cause the MSP430F5659 to restart abnormally. From the log information, we can know that the restart is mainly manifested as 0x02h, 0x04h, 0x20h appear in SYSRSTIV Register.

The specific problem description is that when the system power is turned on, the G-EN is enable and then the MCU will restart. But if we re-powered on immediately, it will be able to start normally. We have tried to remove U23 and just connect R70 for MCU_vcc for power supply, the same problem will occur.

The schematic of MSP430F5659 connected with G-SENSOR is as follows:

The SYSRSTIV Register description.

Can u give us some suggestion for this problem?

Thanks,

Best Regards

over 3 years ago

0 David Schultz over 3 years ago

Guru 25055 points

It might be because the enable pin on U23 is essentially floating when the msp430 is off. A resistor to pull it to the desired state would be a good idea.

Also keeping in mind that when the msp430 is powered down you can get enough current passing through the Vcc clamping diodes on its I/O pins to make it run, or almost run, when external parts provide voltage on its I/O pins.

0 Cash Hao11 over 3 years ago

TI__Mastermind 46765 points

Hi,

I saw in your schematic, the G_EN controls both the U19 and U23. Could you also try to remove the connections to the U19 and keep the U23 for test?

Best regards,

Cash Hao

0 Lumina Gui over 3 years ago in reply to Cash Hao11

Genius 3730 points

Hi Cash,

Our customer also have another question about how MSP430F5659 maintain the RTC by using button battery after power off? Do you have any suggestions on circuit design?

Thanks,

Kind Regards

0 Cash Hao11 over 3 years ago in reply to Lumina Gui

TI__Mastermind 46765 points

Hi,

There is one example code about using the RTC in LPM3 mode here. https://dev.ti.com/tirex/explore/node?node=AJiUjrq7C9e0wXNErLuq.w__IOGqZri__LATEST

Is it enough for your customer?

Best regards,

Cash Hao

0 Lumina Gui over 3 years ago in reply to Cash Hao11

Genius 3730 points

Hi Cash,

Thanks a lot. But our customer was also wondering what needs to be paid attention to in hardware design. Whether only the bat pins need to be connected? Or some other external components also needed.

Best Regards,

Lumina

0 Cash Hao11 over 3 years ago in reply to Lumina Gui

TI__Mastermind 46765 points

Hi,

Is there any accuracy requirement on the RTC block for your customer? If needed, an external LFXT will be needed on the hardware design.

Best regards,

Cash Hao

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MSP430F5659: Abnormal restart problem