TM4C1294KCPDT: Reading DRV8860 Fault Register

Rani Loganathan

Part Number: TM4C1294KCPDT
Other Parts Discussed in Thread: DRV8860

Hi,

I am using TM4C1294KCPDT coustom board interfacing DRV8860 to control outputs . Here I can Control my output pins through DRV 8860 Write command .But I couldnt read fault register . Is there any mistake please correct me.

DRV_Special_Command(1,2,2,3);
on(0xf0);
SysCtlDelay(1000);

DRV_Special_Command(1,2,4,3);
SysCtlDelay(1000);

DRV_Special_Command(1,4,4,3);
DRVRead();
SysCtlDelay(1000);

DRV_Special_Command(1,4,2,3);
DRVRead();
SysCtlDelay(1000);
off(0xff);

void DRVRead()
{

unsigned char x;
DRV8860_clk_High
DRV8860_Latch_High
DRV8860_clk_Low
DRV8860_Latch_Low
DRV8860_clk_High;
DRV8860_Latch_High

for(x=0;x<8;x++)
{
DRV8860_clk_High
SysCtlDelay(130);
DRV8860_clk_Low
SysCtlDelay(110);
fault <<= 1;
if( GPIOPinRead(GPIO_PORTD_BASE, 0))
fault |= 1;

}

SysCtlDelay(110);

}

void DRV_Special_Command(uint8_t part1,uint8_t part2, uint8_t part3, uint8_t part4)
{

uint8_t i;

DRV8860_Latch_High
DRV8860_clk_Low
DRV8860_Latch_Low
for (i = 0; i < part1; i++)
{
DRV8860_clk_High
DRV8860_clk_Low

}
DRV8860_Latch_High

DRV8860_Latch_Low
for (i = 0; i < part2; i++)
{
DRV8860_clk_High
DRV8860_clk_Low
}
DRV8860_Latch_High

DRV8860_Latch_Low
for (i = 0; i < part3; i++)
{
DRV8860_clk_High
DRV8860_clk_Low
}
DRV8860_Latch_High

DRV8860_Latch_Low
for (i = 0; i < part4; i++)
{

DRV8860_clk_High
DRV8860_clk_Low
}
DRV8860_Latch_High
}

Thanks in advance.

Regards,

Rani

over 2 years ago

0 Shinya Morita over 2 years ago

TI__Mastermind 24735 points

Monday is a US holiday. One of my colleagues will respond on Tuesday.

Best regards,

0 Shinya Morita over 2 years ago in reply to Shinya Morita

TI__Mastermind 24735 points

Hi,

Let me attach past E2E post for similar question.

https://e2e.ti.com/support/motor-drivers-group/motor-drivers/f/motor-drivers-forum/845522/drv8860-fault-register-read-waveform-error

First the first read, it is necessary to keep clk HIGH before before doing a read of fault register. If not, data is shifted one bit. We can see the code that shows this and also scope captures from Rick Duncan. This might be the issue.

I would like to recommend to capture waveform of serial interface and compare with this case.

Thanks

regards

Shinya Morita

0 Rani Loganathan over 2 years ago in reply to Shinya Morita

Prodigy 30 points

Hi Shinya Morita,

In DRV8860 without Write Special command i can able to Control the output valves .Is there any possiblities to Read fault register without Special Command ?

Thanks

Regards,

Rani

0 Rani Loganathan over 2 years ago in reply to Shinya Morita

Prodigy 30 points

Hi Shinya Morita,

I have configured 8 pins , load is connected in only one pin . So when I read fault register I would get open load values through Dout pin Am i Correct? But i didn't get any value in this ?? can you please correct me is there mistake in coding ....

Thanks in advance

Regards,

Rani L

0 Rani Loganathan over 2 years ago in reply to Shinya Morita

Prodigy 30 points

Hi Shinya Morita,

Thanks in advance

Regards,

Rani L

0 Shinya Morita over 2 years ago in reply to Rani Loganathan

TI__Mastermind 24735 points

Hi Rain,

Thank you for your follow up questions.

-To read out fault status, special command is not mandatory.

-nFAULT pin indicate whether DRV has fault or not al least. This can be used for sanity check about fault status without serial communication.

-Open Load is not available on DRV8860A. I guess you are testing DRV8860.

-Yes, your understanding is correct. But Open load detection is only while output is in off state. Open load faults are automatically cleared whenever the corresponding output is turned on by setting the Data register bit to ‘1’.(Datasheet 8.3.3.2)

regards

Shinya Morita

0 Rani Loganathan over 2 years ago in reply to Shinya Morita

Prodigy 30 points

Shinya Morita,

Thanks for the cleare clarification . I have one more doubt in this written data register as 0 for some pins , then not to connect any Load in this pins ...Its Shows Fault or not while reading ???

Shinya Morita said:
Yes, your understanding is correct. But Open load detection is only while output is in off state. Open load faults are automatically cleared whenever the corresponding output is turned on by setting the Data register bit to ‘1’.(Datasheet 8.3.3.2)

Thanks in advance

Regards,

Rani

0 Shinya Morita over 2 years ago in reply to Rani Loganathan

TI__Mastermind 24735 points

Hi Rani,

Thank you for your feedback. It is description on datasheet and intended function.

regards

Shinya Morita

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TM4C1294KCPDT: Reading DRV8860 Fault Register