topic Re: MC33HB2000 SPI communication error in Powertrain and Electrification Analog Drivers

MC33HB2000 SPI communication error

hyjung — Fri, 24 Mar 2023 07:48:50 GMT

Dear all.

I send detailed waveform data regarding whether or not a damping resistor 1kohm is inserted in SPI line between the MCU and the MC33HB2000.

test condition)

When waking up from sleep, it operates for 15 seconds after initializing for 100 ms

SPI freq. 500 kHz, Motor current 1.5A max.

What is the reason for the difference caused by the presence or absence of the damping resistance of the SLK line?

Thanks.

Re: MC33HB2000 SPI communication error

Wayne_Anderson — Fri, 24 Mar 2023 20:36:25 GMT

Hi,

Not understanding question. The want to use damping resistor on SCLK line? 1kohm seems quite large.

Wayne

Re: MC33HB2000 SPI communication error

hyjung — Mon, 27 Mar 2023 00:26:34 GMT

Dear Anderson.

The reason for using the damping resistor was added due to EMC CE current NG.
I need to use a damping resistor for the SCLK line. Is there a way to determine the application range of the damping resistor because the following problem has occurred?
And why does the error appear when 1kohm is applied?

Thanks.

Re: MC33HB2000 SPI communication error

Wayne_Anderson — Mon, 27 Mar 2023 17:41:11 GMT

Hello,

Ensure you have adequate hold time. SCLK falling edge to MOSI requires a minimum 30ns hold timing.

Re: MC33HB2000 SPI communication error

hyjung — Mon, 03 Apr 2023 01:14:28 GMT

Thanks for your response.

If MOSI fails to reach the hold time, does MISO send an error?
What I do not understand is why MISO sends an error even though it is not actually an error in the motor driver.

Thanks.

Re: MC33HB2000 SPI communication error

Wayne_Anderson — Mon, 03 Apr 2023 17:33:52 GMT

Hi,

What is the error you are detecting in the status register? Are you getting a SPI framing error? If the number of clock pulses within CS_B low is not more than 0 and an integer multiple of 16, the current SPI communication is ignored and a framing error is recorded in the status register. Do you have inadvertent Chip Select going low?