Power ManagementのトピックRe: S32K312 + MC33771B SPI Speed

S32K312 + MC33771B SPI Speed

kjy106906 — Wed, 05 Jul 2023 06:27:52 GMT

Hello

I am currently using the S32K312 + MC33771B combination.
SPI Speed is 4Mhz.
It took longer than expected to read the registers of the MC33771, so I checked the waveform.
The interval between frames (5 bytes) and between frames (90us) was too long.
How can I reduce the gap between frames.
I am using the Spi_SyncTransmit function.

Thank you

kjy106906_0-1688538329936.png

(Spi_SyncTransmit(MC33771B) -> Spi_SyncTransmit(MC33771B) without delay )

Re: S32K312 + MC33771B SPI Speed

guoweisun — Fri, 07 Jul 2023 03:35:03 GMT

You can refer to below link for MC33771B:

MC33771B | 14-Channel Li-ion Battery Cell Controller IC | NXP Semiconductors

Re: S32K312 + MC33771B SPI Speed

kjy106906 — Fri, 07 Jul 2023 04:46:01 GMT

I couldn't find the answer to my question in that link.
A specific answer would be appreciated.

Re: S32K312 + MC33771B SPI Speed

guoweisun — Tue, 11 Jul 2023 05:20:35 GMT

In that link there is a example code for reference, you can download it and try test again.

guoweisun_0-1689052818520.png

Re: S32K312 + MC33771B SPI Speed

kjy106906 — Tue, 11 Jul 2023 06:26:01 GMT

I think it's no different than my way.
I don't have any difficulties in implementing it, and I'm asking about the time.
I am using S32K312 (RTD) + Microsar OS.
If it's fast in your environment, please share the 2 frame SPI waveform.

Re: S32K312 + MC33771B SPI Speed

guoweisun — Tue, 11 Jul 2023 08:09:54 GMT

OK,for your test waveform, could you please explain the test name of these four channels?

Re: S32K312 + MC33771B SPI Speed

kjy106906 — Tue, 11 Jul 2023 09:06:22 GMT

S32K312 (RTD) + in Microsar OS environment
I want to reduce the delay between frames.

Yellow = SPI Clock
Red = MOSI
BLUE = MISO
Green = CS

Thank u

Re: S32K312 + MC33771B SPI Speed

guoweisun — Wed, 12 Jul 2023 00:58:29 GMT

I am not familiar with the Spi_SyncTransmit function code, but in your test waveform the green line means the CS line should pull low for active the SPI communication. The 90us interval happened on CS high.

guoweisun_0-1689123437918.png

Re: S32K312 + MC33771B SPI Speed

kjy106906 — Wed, 12 Jul 2023 01:04:15 GMT

Yeah, that's why I said I want to reduce the gap between the two frames. (The part where CS is High)
Any other engineers familiar with the Spi_SyncTransmit function?

Re: S32K312 + MC33771B SPI Speed

guoweisun — Wed, 12 Jul 2023 01:26:57 GMT

Please submit ticket for this topic ,I discuss with MCU colleague who told this driver is written by them.

They can support to you!

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